(Slip Opinion)              OCTOBER TERM, 2018                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

   STURGEON v. FROST, IN HIS OFFICIAL CAPACITY AS
  ALASKA REGIONAL DIRECTOR OF THE NATIONAL
             PARK SERVICE, ET AL.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE NINTH CIRCUIT

   No. 17–949.      Argued November 5, 2018—Decided March 26, 2019
The Alaska National Interest Lands Conservation Act (ANILCA) set
  aside 104 million acres of federally owned land in Alaska for preser-
  vation purposes. With that land, ANILCA created ten new national
  parks, monuments, and preserves (areas known as “conservation sys-
  tem units”). 16 U. S. C. §3102(4). And in sketching those units’
  boundary lines, Congress made an uncommon choice—to follow natu-
  ral features rather than enclose only federally owned lands. It thus
  swept in a vast set of so-called inholdings—more than 18 million
  acres of state, Native, and private land. Had Congress done nothing
  more, those inholdings could have become subject to many National
  Park Service rules, as the Service has broad authority under its Or-
  ganic Act to administer both lands and waters within parks across
  the country. 54 U. S. C. §100751. But Congress added Section
  103(c), the provision principally in dispute in this case. Section
  103(c)’s first sentence states that “[o]nly” the “public lands”—defined
  as most federally owned lands, waters, and associated interests—
  within any system unit’s boundaries are “deemed” a part of that unit.
  16 U. S. C. §3103(c). The second sentence provides that no state, Na-
  tive, or private lands “shall be subject to the regulations applicable
  solely to public lands within [system] units.” Ibid. And the third
  sentence permits the Service to “acquire such lands” from “the State,
  a Native Corporation, or other owner,” after which it may “adminis-
  ter[ ]” the land just as it does the other “public lands within such
  units.” Ibid.
     Petitioner John Sturgeon traveled for decades by hovercraft up
  a stretch of the Nation River that lies within the boundaries of the
2                         STURGEON v. FROST

                                  Syllabus

    Yukon-Charley Preserve, a conservation system unit in Alaska. On
    one such trip, Park rangers informed him that the Service’s rules
    prohibit operating a hovercraft on navigable waters “located within [a
    park’s] boundaries.” 36 CFR §2.17(e). That regulation—issued under
    the Service’s Organic Act authority—applies to parks nationwide
    without any “regard to the ownership of submerged lands, tidelands,
    or lowlands.” §1.2(a)(3). Sturgeon complied with the order, but
    shortly thereafter sought an injunction that would allow him to re-
    sume using his hovercraft on his accustomed route. The District
    Court and the Ninth Circuit denied him relief, interpreting Section
    103(c) to limit only the Service’s authority to impose Alaska-specific
    regulations on inholdings—not its authority to enforce nationwide
    regulations like the hovercraft rule. This Court granted review and
    rejected that ground for dismissal, but it remanded for consideration
    of two further questions: whether the Nation River “qualifies as ‘pub-
    lic land’ for purposes of ANILCA,” thus indisputably subjecting it to
    the Service’s regulatory authority; and, if not, whether the Service
    could nevertheless “regulate Sturgeon’s activities on the Nation Riv-
    er.” Sturgeon v. Frost, 577 U. S. ___, ___–___ (Sturgeon I). The Ninth
    Circuit never got past the first question, as it concluded that the Na-
    tion River was public land.
Held:
    1. The Nation River is not public land for purposes of ANILCA.
 “[P]ublic land” under ANILCA means (almost all) “lands, waters, and
 interests therein” the “title to which is in the United States.” 16
 U. S. C. §3102(1)–(3). Because running waters cannot be owned, the
 United States does not have “title” to the Nation River in the ordi-
 nary sense. And under the Submerged Lands Act, it is the State of
 Alaska—not the United States—that holds “title to and ownership of
 the lands beneath [the River’s] navigable waters.” 43 U. S. C. §1311.
 The Service therefore argues that the United States has “title” to an
 “interest” in the Nation River under the reserved-water-rights doc-
 trine, which provides that when the Federal Government reserves
 public land, it can retain rights to the specific “amount of water”
 needed to satisfy the purposes of that reservation. See Cappaert v.
 United States, 426 U. S. 128, 138–141. But even assuming that the
 Service held such a right, the Nation River itself would not thereby
 become “public land” in the way the Service contends. Under ANILCA,
 the “public land” would consist only of the Federal Government’s spe-
 cific “interest” in the River—i.e., its reserved water right. And that
 right, the Service agrees, merely allows it to protect waters in the
 park from depletion or diversion. The right could not justify applying
 the hovercraft rule on the Nation River, as that rule targets nothing
 of the kind. Pp. 12–15.
                    Cite as: 587 U. S. ____ (2019)                       3

                               Syllabus

  2. Non-public lands within Alaska’s national parks are exempt
from the Park Service’s ordinary regulatory authority. Section 103(c)
arose out of concern from the State, Native Corporations, and private
individuals that ANILCA’s broadly drawn boundaries might subject
their properties to Park Service rules. Section 103(c)’s first sentence
therefore sets out which land within those new parks qualify as park-
land—“[o]nly” the “public lands” within any system unit’s boundaries
are “deemed” a part of that unit. By negative implication, non-public
lands are “deemed” outside the unit. In other words, non-federally
owned lands inside system units (on a map) are declared outside
them (for the law). The effect of that exclusion, as Section 103(c)’s
second sentence affirms, is to exempt non-public lands, including wa-
ters, from Park Service regulations. That is, the Service’s rules will
apply “solely” to public lands within the units. 16 U. S. C. §3103(c).
And for that reason, the third sentence provides a kind of escape
hatch—it allows the Service to acquire inholdings when it believes
regulation of those lands is needed.
  The Service’s alternative interpretation of Section 103(c) is unper-
suasive. The provision’s second sentence, it says, means that if a
Park Service regulation on its face applies “solely” to public lands,
then the regulation cannot apply to non-public lands. But if instead
the regulation covers public and non-public lands alike, then the sec-
ond sentence has nothing to say: The regulation can indeed cover
both. On that view, Section 103(c)’s second sentence is a mere tru-
ism, not any kind of limitation. It does nothing to exempt inholdings
from any regulation that might otherwise apply. And because that is
so, the Government’s reading also strips the first and third sentences
of their core functions. The first sentence’s “deeming” has no point,
since there is no reason to pretend that inholdings are not part of a
park if they can still be regulated as parklands. And the third sen-
tence’s acquisition option has far less utility if the Service has its full
regulatory authority over lands the Federal Government does not
own. This sort of statute-gutting cannot be squared with ANILCA’s
text and context. Pp. 16–26.
  3. Navigable waters within Alaska’s national parks—no less than
other non-public lands—are exempt from the Park Service’s normal
regulatory authority. The Service argues that, if nothing else,
ANILCA must at least allow it to regulate navigable waters. The
Act, however, does not readily allow the decoupling of navigable wa-
ters from other non-federally owned areas in Alaskan national parks.
ANILCA defines “land” to mean “lands, waters, and interests there-
in,” §3102(1)–(3); so when it refers to “lands” in Section 103(c) (and
throughout the Act) it means waters as well. Nothing in the few
aquatic provisions to which the Service points conflicts with reading
4                         STURGEON v. FROST

                                  Syllabus

    Section 103(c)’s regulatory exemption to cover navigable waters. The
    Government largely relies on the Act’s statements of purpose, but
    this Court’s construction leaves the Service with multiple tools to
    “protect” and “preserve” rivers in Alaska’s national parks, as those
    provisions anticipate. See, e.g., §§3181(j), 3191(b)(7). While such au-
    thority might fall short of the Service’s usual power, it accords with
    ANILCA’s “repeated[ ] recogni[tion]” that Alaska is “the exception,
    not the rule.” Sturgeon I, 577 U. S., at ___. Pp. 26–29.
872 F. 3d 927, reversed and remanded.

   KAGAN, J., delivered the opinion for a unanimous Court. SOTOMAYOR,
J., filed a concurring opinion, in which GINSBURG, J., joined.
                       Cite as: 587 U. S. ____ (2019)                              1

                            Opinion of the Court

    NOTICE: This opinion is subject to formal revision before publication in the
    preliminary print of the United States Reports. Readers are requested to
    notify the Reporter of Decisions, Supreme Court of the United States, Wash-
    ington, D. C. 20543, of any typographical or other formal errors, in order
    that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                  _________________

                                  No. 17–949
                                  _________________


  JOHN STURGEON, PETITIONER v. BERT FROST,
  IN HIS OFFICIAL CAPACITY AS ALASKA
                               REGIONAL DI-
 RECTOR OF THE NATIONAL PARK SERVICE, ET AL.
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
            APPEALS FOR THE NINTH CIRCUIT
                               [March 26, 2019]

   JUSTICE KAGAN delivered the opinion of the Court.
   This Court first encountered John Sturgeon’s lawsuit
three Terms ago. See Sturgeon v. Frost, 577 U. S. ___
(2016) (Sturgeon I ). As we explained then, Sturgeon
hunted moose along the Nation River in Alaska for some
40 years. See id., at ___ (slip op., at 1). He traveled by
hovercraft, an amphibious vehicle able to glide over land
and water alike. To reach his favorite hunting ground, he
would pilot the craft over a stretch of the Nation River
that flows through the Yukon-Charley Rivers National
Preserve, a unit of the federal park system managed by
the National Park Service. On one such trip, park rangers
informed Sturgeon that a Park Service regulation prohib-
its the use of hovercrafts on rivers within any federal
preserve or park. Sturgeon complied with their order to
remove his hovercraft from the Yukon-Charley, thus
“heading home without a moose.” Id., at ___ (slip op., at
6). But soon afterward, Sturgeon sued the Park Service,
seeking an injunction that would allow him to resume
using his hovercraft on his accustomed route. The lower
2                   STURGEON v. FROST

                     Opinion of the Court

courts denied him relief. This Court, though, thought
there was more to be said. See id., at ___–___ (slip op., at
15–16).
   As we put the matter then, Sturgeon’s case raises the
issue how much “Alaska is different” from the rest of the
country—how much it is “the exception, not the rule.” Id.,
at ___–___ (slip op., at 13–14). The rule, just as the rang-
ers told Sturgeon, is that the Park Service may regulate
boating and other activities on waters within national
parks—and that it has banned the use of hovercrafts
there. See 54 U. S. C. §100751(b); 36 CFR §2.17(e) (2018).
But Sturgeon claims that Congress created an Alaska-
specific exception to that broad authority when it enacted
the Alaska National Interest Lands Conservation Act
(ANILCA), 94 Stat. 2371, 16 U. S. C. §3101 et seq. In
Alaska, Sturgeon argues, the Park Service has no power to
regulate lands or waters that the Federal Government
does not own; rather, the Service may regulate only what
ANILCA calls “public land” (essentially, federally owned
land) in national parks. And, Sturgeon continues, the
Federal Government does not own the Nation River—so
the Service cannot ban hovercrafts there. When we last
faced that argument, we disagreed with the reason the
lower courts gave to reject it. But we remanded the case
for consideration of two remaining questions. First, does
“the Nation River qualif[y] as ‘public land’ for purposes of
ANILCA”? 577 U. S., at ___ (slip op., at 15). Second,
“even if the [Nation] is not ‘public land,’ ” does the Park
Service have authority to “regulate Sturgeon’s activities”
on the part of the river in the Yukon-Charley? Id., at ___
(slip op., at 16). Today, we take up those questions, and
answer both “no.” That means Sturgeon can again rev up
his hovercraft in search of moose.
                  Cite as: 587 U. S. ____ (2019)            3

                      Opinion of the Court

                               I
                               A
  We begin, as Sturgeon I did, with a slice of Alaskan
history. The United States purchased Alaska from Russia
in 1867. It thereby acquired “[i]n a single stroke” 365
million acres of land—an area more than twice the size of
Texas. Id., at ___ (slip op., at 2). You might think that
would be enough to go around. But in the years since, the
Federal Government and Alaskans (including Alaska
Natives) have alternately contested and resolved and
contested and . . . so forth who should own and manage
that bounty. We offer here a few highlights because they
are the backdrop against which Congress enacted
ANILCA. As we do so, you might catch a glimpse of some
former-day John Sturgeons—who (for better or worse)
sought greater independence from federal control and, in
the process, helped to shape the current law.
  For 90 years after buying Alaska, the Federal Govern-
ment owned all its land. At first, those living in Alaska—a
few settlers and some 30,000 Natives—were hardly aware
of that fact. See E. Gruening, The State of Alaska 355
(1968). American citizens mocked the Alaska purchase as
Secretary of State “Seward’s Folly” and President John-
son’s “Polar Bear Garden.” They paid no attention to the
new area, leading to an “era of total neglect.” Id., at 31.
But as Sturgeon I recounted, the turn of the century
brought “newfound recognition of Alaska’s economic po-
tential.” 577 U. S., at ___ (slip op., at 2). Opportunities to
mine, trap, and fish attracted tens of thousands more
settlers and sparked an emerging export economy. And
partly because of that surge in commercial activity, the
country’s foremost conservationists—President Theodore
Roosevelt and Gifford Pinchot, chief of the fledgling Forest
Service—took unprecedented action to protect Alaska’s
natural resources. In particular, Roosevelt (and then
President Taft) prevented settlers from logging or coal
4                  STURGEON v. FROST

                     Opinion of the Court

mining on substantial acreage. See W. Borneman, Alaska:
Saga of a Bold Land 240–241 (2003). Alaskans responded
by burning Pinchot in effigy and, more creatively, organiz-
ing the “Cordova Coal Party”—a mass dumping of imported
Canadian coal (instead of English tea) into the Pacific
Ocean (instead of Boston Harbor). See ibid. The terms of
future conflict were thus set: resource conservation vs.
economic development, federal management vs. local
control.
   By the 1950s, Alaskans hankered for both statehood and
land—and Congress decided to give them both. In press-
ing for statehood, Alaska’s delegate to the House of Repre-
sentatives lamented that Alaskans were no better than
“tenants upon the estate of the national landlord”; and
Alaska’s Governor (then a Presidential appointee) called
on the country to “[e]nd American [c]olonialism.” W.
Everhart, The National Park Service 126–127 (1983)
(Everhart). Ever more aware of Alaska’s economic and
strategic importance, Congress agreed the time for state-
hood had come. The 1958 Alaska Statehood Act, 72 Stat.
339, made Alaska the country’s 49th State. And because
the new State would need property—to propel private
industry and create a tax base—the Statehood Act made a
land grant too. Over the next 35 years, Alaska could
select for itself 103 million acres of “vacant, unappropri-
ated, and unreserved” federal land—an area totaling the
size of California. §§6(a)–(b), 72 Stat. 340, as amended;
see Everhart 127. And more: By incorporating the Sub-
merged Lands Act of 1953, the Statehood Act gave Alaska
“title to and ownership of the lands beneath navigable
waters,” such as the Nation River. 43 U. S. C. §1311; see
§6(m), 72 Stat. 343. And a State’s title to the lands be-
neath navigable waters brings with it regulatory authority
over “navigation, fishing, and other public uses” of those
waters. United States v. Alaska, 521 U. S. 1, 5 (1997). All
told, the State thus emerged a formidable property holder.
                 Cite as: 587 U. S. ____ (2019)            5

                     Opinion of the Court

   But the State’s bonanza provoked land claims from
Alaska Natives. Their ancestors had lived in the area for
thousands of years, and they asserted aboriginal title to
much of the property the State was now taking (and more
besides). See Everhart 127. When their demands threat-
ened to impede the trans-Alaska pipeline, Congress
stepped in. The Alaska Native Claims Settlement Act of
1971 (ANCSA) extinguished the Natives’ aboriginal
claims. See 85 Stat. 688, as amended, 43 U. S. C. §1601 et
seq. But it granted the Natives much in return. Under
the law, corporations organized by groups of Alaska Na-
tives could select for themselves 40 million acres of federal
land—equivalent, when combined, to all of Pennsylvania.
See §§1605, 1610–1615. So the Natives became large
landowners too.
   Yet one more land dispute loomed. In addition to set-
tling the Natives’ claims, ANCSA directed the Secretary of
the Interior (Secretary) to designate, subject to congres-
sional approval, 80 million more acres of federal land for
inclusion in the national park, forest, or wildlife systems.
See §1616(d)(2). The Secretary dutifully made his selec-
tions, but Congress failed to ratify them within the five-
year period ANCSA had set. Rather than let the designa-
tions lapse, President Carter invoked another federal law
(the 1906 Antiquities Act) to proclaim most of the lands
(totaling 56 million acres) national monuments, under the
National Park Service’s aegis. See 577 U. S., at ___ (slip
op., at 4). Many Alaskans balked. “[R]egard[ing] national
parks as just one more example of federal interference,”
protesters demonstrated throughout the State and several
thousand joined in the so-called Great Denali-McKinley
Trespass. Everhart 129; see 577 U. S., at ___ (slip op., at
4). “The goal of the trespass,” as Sturgeon I explained,
“was to break over 25 Park Service rules in a two-day
period.” Ibid. One especially eager participant played a
modern-day Paul Revere, riding on horseback through the
6                   STURGEON v. FROST

                      Opinion of the Court

crowd to deliver the message: “The Feds are coming!
The Feds are coming!” Ibid. (internal quotation marks
omitted).
   And so they were—but not in quite the way President
Carter had contemplated. Responding to the uproar his
proclamation had set off, Congress enacted a third major
piece of legislation allocating land in Alaska. We thus
reach ANILCA, the statute principally in dispute in this
case, in which Congress set aside extensive land for na-
tional parks and preserves—but on terms different from
those governing such areas in the rest of the country.
                               B
   Starting with the statement of purpose in its first sec-
tion, ANILCA sought to “balance” two goals, often thought
conflicting. 16 U. S. C. §3101(d). The Act was designed to
“provide[] sufficient protection for the national interest in
the scenic, natural, cultural and environmental values on
the public lands in Alaska.” Ibid. “[A]nd at the same
time,” the Act was framed to “provide[] adequate oppor-
tunity for satisfaction of the economic and social needs of
the State of Alaska and its people.” Ibid. So if, as you
continue reading, you see some tension within the statute,
you are not mistaken: It arises from Congress’s twofold
ambitions.
   ANILCA set aside 104 million acres of federally owned
land in Alaska for preservation purposes. See 577 U. S.,
at ___ (slip op., at 5). In doing so, the Act rescinded Presi-
dent Carter’s monument designations. But it brought into
the national park, forest, or wildlife systems millions more
acres than even ANCSA had contemplated. The park
system’s share of the newly withdrawn land (to be admin-
istered, as usual, by the Park Service) was nearly 44
million acres—an amount that more than doubled the
system’s prior (nationwide) size. See Everhart 132. With
that land, ANILCA created ten new national parks, mon-
                 Cite as: 587 U. S. ____ (2019)           7

                     Opinion of the Court

uments, and preserves—including the Yukon-Charley
Preserve—and expanded three old ones. See §§410hh,
410hh–1. In line with the Park Service’s usual terminol-
ogy, ANILCA calls each such park or other area a “conser-
vation system unit.” §3102(4) (“The term . . . means any
unit in Alaska of the National Park System”); see 54
U. S. C. §100102(6) (similar).
  In sketching those units’ boundary lines, Congress made
an uncommon choice—to follow “topographic or natural
features,” rather than enclose only federally owned lands.
§3103(b); see Brief for Respondents 24 (agreeing that
“ANILCA [is] atypical in [this] respect”). In most parks
outside Alaska, boundaries surround mainly federal prop-
erty holdings. “[E]arly national parks were carved out of a
larger public domain, in which virtually all land” was
federally owned. Sax, Helpless Giants: The National
Parks and the Regulation of Private Lands, 75 Mich.
L. Rev. 239, 263 (1976); see Dept. of Interior, Nat. Park
Serv., Statistical Abstract 87 (2017) (Table 9) (noting that
only 2 of Yellowstone’s 2.2 million acres are in non-federal
hands). And even in more recently established parks,
Congress has used gerrymandered borders to exclude most
non-federal land. See Sax, Buying Scenery, 1980 Duke
L. J. 709, 712, and n. 12. But Congress had no real way to
do that in Alaska. Its prior cessions of property to the
State and Alaska Natives had created a “confusing patch-
work of ownership” all but impossible to draw one’s way
around. C. Naske & H. Slotnick, Alaska: A History 317
(3d ed. 2011). What’s more, an Alaskan Senator noted, the
United States might want to reacquire state or Native
holdings in the same “natural areas” as reserved federal
land; that could occur most handily if Congress drew
boundaries, “wherever possible, to encompass” those hold-
ings and authorized the Secretary to buy whatever lay
inside. 126 Cong. Rec. 21882 (1980) (remarks of Sen.
Stevens). The upshot was a vast set of so-called inhold-
8                       STURGEON v. FROST

                         Opinion of the Court

ings—more than 18 million acres of state, Native, and
private land—that wound up inside Alaskan system units.
See 577 U. S., at ___–___ (slip op., at 5–6).
  Had Congress done nothing more, those inholdings
could have become subject to many Park Service rules—
the same kind of “restrictive federal regulations” Alaskans
had protested in the years leading up to ANILCA (and
further back too). Id., at ___ (slip op., at 4). That is be-
cause the Secretary, acting through the Director of the
Park Service, has broad authority under the National
Park Service Organic Act (Organic Act), 39 Stat. 535, to
administer both lands and waters within all system units
in the country. See 54 U. S. C. §§100751, 100501, 100102.
The Secretary “shall prescribe such regulations as [he]
considers necessary or proper for the use and management
of System units.” §100751(a). And he may, more specifi-
cally, issue regulations concerning “boating and other
activities on or relating to water located within System
units.” §100751(b). Those statutory grants of power make
no distinctions based on the ownership of either lands or
waters (or lands beneath waters).1 And although the Park
Service has sometimes chosen not to regulate non-
federally owned lands and waters, it has also imposed
major restrictions on their use. Rules about mining and
solid-waste disposal, for example, apply to all lands within
system units “whether federally or nonfederally owned.”
36 CFR §6.2; see §9.2. And (of particular note here) the
Park Service freely regulates activities on all navigable
(and some other) waters “within [a park’s] boundaries”—
once more, “without regard to . . . ownership.” §1.2(a)(3).
So Alaska and its Natives had reason to worry about how

——————
    1 None
         of the parties here have questioned the constitutional validity
of the above statutory grants as applied to inholdings, and we therefore
do not address the issue. Cf. Kleppe v. New Mexico, 426 U. S. 529, 536–
541 (1976); Kansas v. Colorado, 206 U. S. 46, 88–89 (1907).
                 Cite as: 587 U. S. ____ (2019)            9

                     Opinion of the Court

the Park Service would regulate their lands and waters
within the new parks.
  Congress thus acted, as even the Park Service agrees, to
give the State and Natives “assurance that their [lands]
wouldn’t be treated just like” federally owned property.
Tr. of Oral Arg. 50. (It is only—though this is quite a
large “only”—the nature and extent of that assurance that
is in dispute.) The key provision here is Section 103(c),
which contains three sentences that may require some re-
reading. We quote it first in one block; then provide some
definitions; then go over it again a bit more slowly. But
still, you should expect to return to this text as you pro-
ceed through this opinion.
  Section 103(c) provides in full:
    “Only those lands within the boundaries of any con-
    servation system unit which are public lands (as such
    term is defined in this Act) shall be deemed to be in-
    cluded as a portion of such unit. No lands which, be-
    fore, on, or after [the date of ANILCA’s passage], are
    conveyed to the State, to any Native Corporation, or to
    any private party shall be subject to the regulations
    applicable solely to public lands within such units. If
    the State, a Native Corporation, or other owner de-
    sires to convey any such lands, the Secretary may ac-
    quire such lands in accordance with applicable law
    (including this Act), and any such lands shall become
    part of the unit, and be administered accordingly.”
    §3103(c).
  Now for the promised definitions. The term “land,” as
found in all three sentences, actually—and crucially for
this case—“means lands, waters, and interests therein.”
§3102(1). The term “public lands,” in the first two sen-
tences, then means “lands” (including waters and interests
therein) “the title to which is in the United States”—
except for lands selected for future transfer to the State or
10                  STURGEON v. FROST

                     Opinion of the Court

Native Corporations (under the Statehood Act or ANCSA).
§3102(2), (3); see supra, at 4–5. “Public lands” are there-
fore most but not quite all lands (and again, waters and
interests) that the Federal Government owns.
  Finally, to recap. As explained in Sturgeon I, “Section
103(c) draws a distinction between ‘public’ and ‘non-public’
lands within the boundaries of conservation system units
in Alaska.” 577 U. S., at __ (slip op., at 14). Section
103(c)’s first sentence makes clear that only public lands
(again, defined as most federally owned lands, waters, and
associated interests) would be considered part of a system
unit (again, just meaning a national park, preserve, or
similar area). By contrast, state, Native, or private lands
would not be understood as part of such a unit, even
though they in fact fall within its geographic boundaries.
Section 103(c)’s second sentence then expressly exempts
all those non-public lands (the inholdings) from certain
regulations—though exactly which ones, as will soon
become clear, is a matter of dispute. And last, Section
103(c)’s third sentence enables the Secretary to buy any
inholdings. If he does, the lands (because now public)
become part of the park, and may be administered in
the usual way—e.g., without the provision’s regulatory
exemption.
                             C
   We can now return to John Sturgeon, on his way to a
hunting ground alternatively dubbed “Moose Meadows” or
“Sturgeon Fork.” As recounted above, Sturgeon used to
travel by hovercraft up a stretch of the Nation River that
lies within the boundaries of the Yukon-Charley Preserve.
See supra, at 1. Until one day, three park rangers ap-
proached Sturgeon while he was repairing his steering
cable and told him he was violating a Park Service rule.
According to the specified regulation, “[t]he operation or
use of hovercraft is prohibited” on navigable (and some
                   Cite as: 587 U. S. ____ (2019)               11

                       Opinion of the Court

other) waters “located within [a park’s] boundaries,” with-
out any “regard to . . . ownership.” 36 CFR §§2.17(e),
1.2(a)(3); see supra, at 2. That regulation, issued under
the Secretary’s Organic Act authority, applies on its face
to parks across the country. See supra, at 8 (describing
Organic Act). And Sturgeon did not doubt that the Nation
River is a navigable water. But Sturgeon protested that in
Alaska (even though nowhere else) the rule could not be
enforced on a waterway—like, he said, the Nation River—
that is not owned by the Federal Government. And when
his objection got nowhere with the rangers (or with the
Secretary, to whom he later petitioned), Sturgeon stopped
using his hovercraft—but also brought this lawsuit, based
on ANILCA’s Section 103(c).
   In Sturgeon I, we rejected one ground for dismissing
Sturgeon’s case, but remanded for consideration of two
further questions. The District Court and Court of Ap-
peals for the Ninth Circuit had held that even assuming
the Nation River is non-public land, the Park Service
could enforce its hovercraft ban there. See 2013 WL
5888230 (Oct. 30, 2013); 768 F. 3d 1066 (2014). Those two
courts interpreted Section 103(c) to limit only the Service’s
authority to impose Alaska-specific regulations on such
lands—not its authority to apply nationwide regulations
like the hovercraft rule. But we viewed that construction
as “implausible.” 577 U. S., at ___ (slip op., at 15).
ANILCA, we reasoned, “repeatedly recognizes that Alaska
is different.” Id., at ___ (slip op., at 13); see id., at ___ (slip
op., at 14) (The Act “reflect[s] the simple truth that Alaska
is often the exception, not the rule”). Yet the lower courts’
reading would “prevent the Park Service from recognizing
Alaska’s unique conditions”—thus producing a “topsy-
turvy” result. Ibid. Still, we thought two hurdles re-
mained before Sturgeon could take his hovercraft out of
storage. We asked the Court of Appeals to decide whether
the Nation River “qualifies as ‘public land’ for purposes of
12                   STURGEON v. FROST

                      Opinion of the Court

ANILCA,” thus indisputably subjecting it to the Service’s
regulatory authority. Id., at ___ (slip op., at 15). And if
the answer was “no,” we asked the Ninth Circuit to ad-
dress whether the Service, on some different theory from
the one just dispatched, could still “regulate Sturgeon’s
activities on the Nation River.” Id., at ___ (slip op., at 16).
  The Ninth Circuit never got past the first question
because it concluded that the Nation River is “public
land[.]” See 872 F. 3d 927, 936 (2017). The court ex-
plained that it was bound by three circuit decisions con-
struing that term, when used in ANILCA’s provisions
about subsistence fishing, as including all navigable wa-
ters. Id., at 933–934. Accordingly, the court again rejected
Sturgeon’s challenge. Id., at 936.
  And we again granted certiorari. 585 U. S. ___ (2018).
                             II
  We first address whether, as the Ninth Circuit found,
the Nation River is “public land” under ANILCA. As
defined, once again, that term means (almost all) “lands,
waters, and interests therein” the “title to which is in the
United States.” 16 U. S. C. §3102(1)–(3). If the Nation
River comes within that definition, even Sturgeon agrees
that the Park Service may enforce its hovercraft rule in
the stretch traversing the Yukon-Charley. That is because
the Organic Act authorizes the Park Service to regulate
boating and similar activities in parks and other system
units—and under ANILCA’s Section 103(c) those units
include all “public land” within their boundaries. 54
U. S. C. §100751(a)–(b); 16 U. S. C. §3103(c); see supra, at
8–10.
  But the United States does not have “title” (as the just-
quoted definition demands) to the Nation River in the
ordinary sense. As the Park Service acknowledges, run-
ning waters cannot be owned—whether by a government
or by a private party. See FPC v. Niagara Mohawk Power
                 Cite as: 587 U. S. ____ (2019)          13

                     Opinion of the Court

Corp., 347 U. S. 239, 247, n. 10 (1954); Brief for Respond-
ents 33. In contrast, the lands beneath those waters—
typically called submerged lands—can be owned, and the
water regulated on that basis. But that does not help the
Park Service because, as noted earlier, the Submerged
Lands Act gives each State “title to and ownership of the
lands beneath [its] navigable waters.” 43 U. S. C. §1311;
see supra, at 4. That means Alaska, not the United
States, has title to the lands beneath the Nation River.
  So the Park Service argues instead that the United
States has “title” to an “interest” in the Nation River,
under what is called the reserved-water-rights doctrine.
See Brief for Respondents 32–37. The canonical statement
of that doctrine goes as follows: “[W]hen the Federal Gov-
ernment withdraws its land from the public domain and
reserves it for a federal purpose, the Government, by
implication, reserves appurtenant water then unappropri-
ated to the extent needed to accomplish the purpose of the
reservation.” Cappaert v. United States, 426 U. S. 128,
138 (1976). For example, this Court decided that in re-
serving land for an Indian tribe, the Government impliedly
reserved sufficient water from a nearby river to enable
the tribe to farm the area. See Winters v. United States,
207 U. S. 564, 576 (1908). And similarly, we held that in
creating a national monument to preserve a species of fish
inhabiting an underground pool, the United States ac-
quired an enforceable interest in preventing others from
depleting the pool below the level needed for the fish to
survive. See Cappaert, 426 U. S., at 147. According to the
Park Service, the United States has an analogous interest
in the Nation River and other navigable waters in Alaska’s
national parks. “Because th[e] purposes [of those parks]
require that the waters within [them] be safeguarded
against depletion and diversion,” the Service contends,
“Congress’s reservations of park lands also reserved inter-
ests in appurtenant navigable waters.” Brief for Respond-
14                  STURGEON v. FROST

                     Opinion of the Court

ents 35.
  That argument first raises the question whether it is
even possible to hold “title,” as ANILCA uses the term, to
reserved water rights. 16 U. S. C. §3102(2). Those rights,
as all parties agree, are “usufructuary” in nature, meaning
that they are rights for the Government to use—whether
by withdrawing or maintaining—certain waters it does not
own. See Niagara Mohawk Power Corp., 347 U. S., at 246;
Brief for Petitioner 36; Brief for Respondents 36. The
Park Service has found a couple of old cases suggesting
that a person can hold “title” to such usufructuary inter-
ests. See ibid.; Crum v. Mt. Shasta Power Corp., 220 Cal.
295, 307, 30 P. 2d 30, 36 (1934); Radcliff ’s Ex’rs v. Mayor
of Brooklyn, 4 N. Y. 195, 196 (1850). But the more com-
mon understanding, recently noted in another ANILCA
case, is that “reserved water rights are not the type of
property interests to which title can be held”; rather, “the
term ‘title’ applies” to “fee ownership of property” and
(sometimes) to “possessory interests” in property like
those granted by a lease. See Totemoff v. State, 905 P. 2d
954, 965 (Alaska 1995) (collecting cases); Brief for State of
Idaho et al. as Amici Curiae 21–22 (same). And we see no
evidence that the Congress enacting ANILCA meant to
use the term in any less customary and more capacious
sense.
  But even assuming so, the Nation River itself would not
thereby become “public land” in the way the Park Service
argues. Under ANILCA’s definition, the “public land” at
issue would consist only of the Federal Government’s
specific “interest” in the River—that is, its reserved water
right. §3102(1), (3). And that reserved right, by its na-
ture, is limited. It does not give the Government plenary
authority over the waterway to which it attaches. Rather,
the interest merely enables the Government to take or
maintain the specific “amount of water”—and “no more”—
required to “fulfill the purpose of [its land] reservation.”
                     Cite as: 587 U. S. ____ (2019)                  15

                         Opinion of the Court

Cappaert, 426 U. S., at 141. So, for example, in the cases
described above, the Government could control only the
volume of water necessary for the tribe to farm or the fish
to survive. See Winters, 207 U. S., at 576–577; Cappaert,
426 U. S., at 141. And likewise here, the Government
could protect “only th[e] amount of water” in the Nation
River needed to “accomplish the purpose of the [Yukon-
Charley’s] reservation.” Id., at 138, 141.
  And whatever that volume, the Government’s (purported)
reserved right could not justify applying the hovercraft
rule on the Nation River. That right, to use the Park
Service’s own phrase, would support a regulation prevent-
ing the “depletion or diversion” of waters in the River (up
to the amount required to achieve the Yukon-Charley’s
purposes). Brief for Respondents 34–35. But the hover-
craft rule does nothing of that kind. A hovercraft moves
above the water, on a thin cushion of air produced by
downward-directed fans; it does not “deplet[e]” or “div-
er[t]” any water. Nor has the Park Service explained the
hovercraft rule as an effort to protect the Nation River
from pollution or other similar harm. To the contrary,
that rule is directed against the “sight or sound” of “motor-
ized equipment” in remote locations—concerns not related
to safeguarding the water. 48 Fed. Reg. 30258 (1983). So
the Park Service’s “public lands” argument runs aground:
Even if the United States holds title to a reserved water
right in the Nation River, that right (as opposed to title in
the River itself) cannot prevent Sturgeon from wafting
along the River’s surface toward his preferred hunting
ground.2
——————
  2 As noted earlier, the Ninth Circuit has held in three cases—the so-

called Katie John trilogy—that the term “public lands,” when used in
ANILCA’s subsistence-fishing provisions, encompasses navigable
waters like the Nation River. See Alaska v. Babbitt, 72 F. 3d 698
(1995); John v. United States, 247 F. 3d 1032 (2001) (en banc); John v.
United States, 720 F. 3d 1214 (2013); supra, at 12. Those provisions are
16                       STURGEON v. FROST

                          Opinion of the Court

                             III
   We thus move on to the second question we posed in
Sturgeon I, concerning the Park Service’s power to regu-
late even non-public lands and waters within Alaska’s
system units (or, in our unofficial terminology, national
parks). The Service principally relies on that sort of
ownership-indifferent authority in defending its decision to
expel Sturgeon’s hovercraft from the Nation River. See
Brief for Respondents 16–18, 25–32. And we can see why.
If Sturgeon lived in any other State, his suit would not
have a prayer of success. As noted earlier, the Park Ser-
vice has used its Organic Act authority to ban hovercrafts
on navigable waters “located within [a national park’s]
boundaries” without any “regard to . . . ownership.” 36
CFR §§2.17(e), 1.2(a)(3); see supra, at 10–11. And no one
disputes that Sturgeon was driving his hovercraft on a
stretch of the Nation River (a navigable water) inside the
borders of the Yukon-Charley (a national park). So case
closed. Except that Sturgeon lives in Alaska. And as we
have said before, “Alaska is often the exception, not the
rule.” Sturgeon I, 577 U. S., at ___ (slip op., at 14). Here,
Section 103(c) of ANILCA makes it so. As explained be-
low, that section provides that even when non-public
lands—again, including waters—are geographically within
a national park’s boundaries, they may not be regulated as
part of the park. And that means the Park Service’s hov-
ercraft regulation cannot apply there.3
——————
not at issue in this case, and we therefore do not disturb the Ninth
Circuit’s holdings that the Park Service may regulate subsistence
fishing on navigable waters. See generally Brief for State of Alaska as
Amicus Curiae 29–35 (arguing that this case does not implicate those
decisions); Brief for Ahtna, Inc., as Amicus Curiae 30–36 (same).
   3 Because we see, for the reasons given below, no ambiguity as to

Section 103(c)’s meaning, we cannot give deference to the Park Ser-
vice’s contrary construction. See Chevron U. S. A. Inc. v. Natural
Resources Defense Council, Inc., 467 U. S. 837, 842 (1984) (“If the intent
                      Cite as: 587 U. S. ____ (2019)     17

                           Opinion of the Court

  To understand why, first recall how Section 103(c) grew
out of ANILCA’s unusual method for drawing park bound-
aries. See supra, at 7–8. Those lines followed the area’s
“natural features,” rather than (as customary) the Federal
Government’s property holdings. 16 U. S. C. §3103(b).
The borders thus took in immense tracts owned by the
State, Native Corporations, and private individuals. And
as you might imagine, none of those parties was eager to
have its lands newly regulated as national parks. To the
contrary, all of them wanted to preserve the regulatory
status quo—to prevent ANILCA’s maps from subjecting
their properties to the Park Service’s rules. Hence arose
Section 103(c). Cf. Tr. of Oral Arg. 50 (Solicitor General
acknowledging that Section 103(c) responds to the State’s
and Native Corporations’ “concern[s]” about the effects of
“includ[ing their lands] within the outer boundaries” of the
new parks). Now might be a good time to review that
provision, block quoted above. See supra, at 9. In broad
brush strokes, Sturgeon I described it as follows: “Section
103(c) draws a distinction between ‘public’ and ‘non-public’
lands,” including waters, “within the boundaries of [Alas-
ka’s] conservation system units.” 577 U. S., at ___ (slip
op., at 14).
  Section 103(c)’s first sentence sets out the essential
distinction, relating to what qualifies as parkland. It
provides, once again, that “[o]nly” the “public lands” (es-
sentially, the federally owned lands) within any system
unit’s boundaries would be “deemed” a part of that unit.
§3103(c). The non-public lands (everything else) were, by
negative implication, “deemed” not a part of the unit—
even though within the unit’s geographic boundaries. The
key word here is “deemed.” That term is used in legal
materials “[t]o treat (something) as if . . . it were really
something else.” Black’s Law Dictionary 504 (10th ed.
——————
of Congress is clear, that is the end of the matter”).
18                      STURGEON v. FROST

                         Opinion of the Court

2014). Legislators (and other drafters) find the word
“useful” when “it is necessary to establish a legal fiction,”
either by “‘deeming’ something to be what it is not” or by
“‘deeming’ something not to be what it is.” Ibid. (quoting
G.C. Thornton, Legislative Drafting 99 (4th ed. 1996)).
The fiction in Section 103(c) involves considering certain
lands actually within the new national parks as instead
without them. As a matter of geography, both public and
non-public lands fall inside those parks’ boundaries. But
as a matter of law, only public lands would be viewed as
doing so. All non-public lands (again, including waters)
would be “deemed,” abracadabra-style, outside Alaska’s
system units.4
   The effect of that exclusion, as Section 103(c)’s second
sentence affirms, is to exempt non-public lands, including
waters, from the Park Service’s ordinary regulatory au-
thority. Recall that the Organic Act pegs that authority to
system units. See supra, at 8. The Service may issue
rules thought “necessary or proper” for “System units.” 54
U. S. C. §100751(a). And more pertinently here, the Ser-
vice may prescribe rules about activities on “water located
within System units.” §100751(b). Absent Section 103(c),
those grants of power enable the Service to administer
even non-federally owned waters or lands inside national
parks. See supra, at 8. But add Section 103(c), and the
equation changes. Now, according to that section’s first
sentence, non-federally owned waters and lands inside
system units (on a map) are declared outside them (for the
——————
  4 Consistent with that approach, Congress left out non-public lands in
calculating the acreage of every new or expanded system unit. Sections
201 and 202 of ANILCA, in describing those units, state the acreage of
only their public lands. See, e.g., §410hh(1) (providing that Aniakchak
National Preserve would “contain[ ] approximately [367,000] acres of
public lands”); §410hh–1(3) (providing that Denali National Park would
grow “by the addition of an area containing approximately [2,426,000]
acres of public land”).
                     Cite as: 587 U. S. ____ (2019)                    19

                          Opinion of the Court

law). So those areas are no longer subject to the Service’s
power over “System units” and the “water located within”
them. §100751(a), (b). Instead, only the federal property
in system units is subject to the Service’s authority.5 And
that is just what Section 103(c)’s second sentence pro-
nounces, for waters and lands alike. Again, that sentence
says that no state, Native, or private lands “shall be sub-
ject to the regulations applicable solely to public lands
within [system] units.” 16 U. S. C. §3103(c). The sentence
thus expressly states the consequence of the statute’s prior
“deeming.” The Service’s rules will apply exclusively to
public lands (meaning federally owned lands and waters)
within system units. The rules cannot apply to any non-
federal properties, even if a map would show they are
within such a unit’s boundaries. Geographic inholdings
thus become regulatory outholdings, impervious to the
Service’s ordinary authority.6
——————
   5 At times, the Park Service has argued here that the Organic Act

gives it authority to regulate waters outside system units, so long as
doing so protects waters or lands inside them. See Brief for Respond-
ents 28–32. If so, the argument goes, that authority would similarly
permit the Service to regulate the non-federally owned waters that
Section 103(c) has deemed outside Alaskan system units, if and when
needed to conserve those units’ federal waters or lands. But at other
points in this litigation, the Service has all but disclaimed such out-of-
the-park regulatory authority. See No. 14–1209, Tr. of Oral Arg. 58
(Jan. 20, 2016) (“The Park Service [has] consistently understood its
authority to be regulating [within] the park’s boundaries. It’s never
sought to enact a regulation outside of the park’s boundaries”). We
take no position on the question because it has no bearing on the
hovercraft rule at issue here. That rule, by its express terms, applies
only inside system units. See supra, at 10–11. It therefore does not
raise any question relating to the existence or scope of the Service’s
authority over water outside system units.
   6 Another provision of ANILCA reflects that result. Right after Sec-

tions 201 and 202 describe each new or expanded system unit by
reference to how many acres of public land it contains, see n. 4, supra,
Section 203 authorizes the Park Service to administer, under the
Organic Act, the areas listed in “the foregoing sections.” §410hh–2. In
20                     STURGEON v. FROST

                        Opinion of the Court

  And for that reason, Section 103(c)’s third sentence
provides a kind of escape hatch—for times when the Park
Service believes regulation of the inholdings is needed. In
that event, “the Secretary may acquire such lands” from
“the State, a Native Corporation, or other owner.”
§3103(c). (As noted earlier, facilitating those acquisitions
was one reason Congress put non-federal lands inside
park boundaries in the first instance. See supra, at 7.)
When the Secretary makes such a purchase, the newly
federal land “become[s] part of the [system] unit.”
§3101(c). And the Park Service may then “administer[]”
the land just as it does (in the second sentence’s phrase)
the other “public lands within such units.” Ibid. In thus
providing a way out of the Section’s first two sentences,
the third underlines what they are doing: insulating the
state, Native, or private lands that ANILCA enclosed in
national parks from new and unexpected regulation. In
sum, those lands may be regulated only as they could have
been before ANILCA’s enactment, unless and until bought
by the Federal Government.
  The Park Service interprets Section 103(c) differently,
relying wholly on its second sentence and mostly on the
single word “solely” there. True enough, the Service
acknowledges, that anxiety about how it would regulate
inholdings was “really what drove [Section] 103(c).” Tr. of
Oral Arg. 46; see supra, at 9, 17. But still, the Service
argues, the Section’s second sentence exempts those non-
public lands from only “one particular class of Park Ser-
vice regulations”—to wit, rules “ ‘applicable solely to public
lands.’ ” Brief for Respondents 30 (quoting and adding
emphasis to §3103(c)). In other words, if a Park Service
regulation on its face applies only (“solely”) to public lands,
——————
other words, Section 203 of ANILCA ties the Service’s regulatory
authority to the statute’s immediately preceding statements of public-
land acreage.
                     Cite as: 587 U. S. ____ (2019)                  21

                         Opinion of the Court

then the regulation shall not apply to a park’s non-public
lands. But if instead the regulation covers public and non-
public lands alike, then the second sentence has nothing to
say: The regulation can indeed cover both. See ibid. The
Park Service labels that sentence a “tailored limitation” on
its authority over inholdings. Ibid. And it concludes that
the sentence has no bearing on the hovercraft rule, which
expressly applies “without regard to . . . ownership.” 36
CFR §1.2(a)(3).
    But on the Park Service’s view, Section 103(c)’s second
sentence is a mere truism, not any kind of limitation
(however “tailored”). Once again: It tells Alaskans, so the
Park Service says, that rules applying only to public lands
. . . will apply only to public lands. And that rules apply-
ing to both public and non-public lands . . . will apply to
both. (Or, to say the same thing, but with approximate
statutory definitions plugged in: It tells Alaskans that
rules applying only to the Federal Government’s lands . . .
will apply only to the Federal Government’s lands. And
that rules applying to federal, state, Native, and private
lands alike . . . will apply to them all.) In short, under the
Park Service’s reading, Section 103(c)’s second sentence
does nothing but state the obvious. Its supposed exemp-
tion does not in fact exempt anyone from anything to
which they would otherwise be subject. Remove the sen-
tence from ANILCA and everything would be precisely the
same. For it curtails none of the Service’s ordinary regu-
latory authority over inholdings.7
——————
  7 And just to pile on: Even taken as a truism, the Park Service’s view
of the second sentence misfires, because of the technical difference
between “public lands” and federally owned lands in ANILCA. Recall
that “public lands” is defined in the statute to mean most but not all
federally owned lands: The term excludes those federal lands selected
for future transfer to the State or Native Corporations. See §3102(3);
supra, at 9–10. (That is why when we reframed the Park Service’s
argument just above, we noted that we were using “approximate”
22                      STURGEON v. FROST

                         Opinion of the Court

   And more: The Park Service’s reading of Section 103(c)’s
second sentence also strips the first and third sentences of
their core functions. Under the Service’s approach, the
first sentence’s “deeming” has no point. There is no reason
to pretend that inholdings are not part of a park if they
can still be regulated as parklands. Nor is there a need to
create a special legal fiction if the end result is to treat
Alaskan inholdings no differently from those in the rest of
the country. And similarly, the third sentence’s acquisi-
tion option has far less utility if the Service has its full
regulatory authority over lands the Federal Government
does not own. Why cough up money to “administer[ ]”
property as “part of the [system] unit” unless doing so
makes a real difference, by removing a regulatory exemp-
tion otherwise in effect? The Service’s reading effectively
turns the whole of Section 103(c) into an inkblot.
   And still more (if implicit in all the above): That con-
struction would undermine ANILCA’s grand bargain.
Recall that ANILCA announced its Janus-faced nature in
its statement of purpose, reflecting the century-long
struggle over federal regulation of Alaska’s resources. See
supra, at 3–6. In that opening section, ANILCA spoke
about safeguarding “natural, scenic, historic[,] recreational,
and wildlife values.” 16 U. S. C. §3101(a). Yet it in-
sisted as well on “provid[ing] for” Alaska’s (and its citi-
zens’) “economic and social needs.” §3101(d). In keeping
with the statute’s conservation goal, Congress reserved

——————
statutory definitions.) But the Park Service’s existing regulations
apply, at a minimum, to all federally owned lands within a park’s
borders. See 36 CFR §1.2(a). That means there are no regulations
“applicable solely to public lands” as defined in ANILCA. §3103(c). So
when the Park Service argues that the second sentence exempts non-
public lands from that single “class of [its] regulations,” Brief for
Respondents 18, 30, it is not even exempting those lands from obviously
inapplicable regulations (as we assume in the text); instead, it is
exempting them from a null set of rules.
                    Cite as: 587 U. S. ____ (2019)                  23

                         Opinion of the Court

huge tracts of land for national parks. But to protect
Alaskans’ economic well-being, it mitigated the conse-
quences to non-federal owners whose land wound up in
those new system units. See supra, at 17–20. Once again,
even the Park Service acknowledges that Section 103(c)
was supposed to provide an “assurance” that those owners
would not be subject to all the regulatory constraints
placed on neighboring federal properties. See Tr. of Oral
Arg. 50; see id., at 46–47; supra, at 9, 17, 20. But then the
Service (head-spinningly) posits that it need only draft its
regulations to cover both federal and non-federal lands in
order to apply those rules to ANILCA’s inholdings. On
that view, limitations on the Service’s authority are purely
a matter of administrative grace, dependent on how nar-
rowly (or broadly) the Service chooses to write its regula-
tions. And ANILCA’s carefully drawn balance is thrown
off-kilter, as Alaskan, Native, and private inholdings
are exposed to the full extent of the Service’s regulatory
authority.
   The word “solely” in Section 103(c)’s second sentence
does not support that kind of statute-gutting. We do not
gainsay that the Park Service has identified a grammati-
cally possible way of viewing that word’s function: as
pinpointing a narrow class of the Service’s regulations
(those “solely applicable to public lands”).8 But that read-
ing, for all the reasons just stated, is “ultimately incon-
sistent” with the “text and context of the statute.” Stur-
geon I, 577 U. S., at ___ (slip op., at 12). And a different
understanding of “solely” instead aligns with that text and
context. That word encapsulates Congress’s view that the
Park Service’s regulations should apply “solely” to public
lands (and not to state, Native, or private ones). See
——————
  8 It is unfortunate for the Park Service’s argument that the narrow

class of regulations thus identified does not in fact exist. See n. 7,
supra. But we put that point aside for the remainder of this paragraph.
24                       STURGEON v. FROST

                          Opinion of the Court

supra, at 19, and n. 5. And the word serves to distinguish
between the Park Service’s rules and other regulations,
both federal and state. Consider if Congress had exempted
non-public lands in a system unit from regulations
“applicable to public lands” there (without the “solely”).
That language would apparently exempt those lands not
just from park regulations but from a raft of others—e.g.,
pollution regulations of the Environmental Protection
Agency, water safety regulations of the Coast Guard, even
employment regulations of Alaska itself. For those rules,
too, apply to public lands inside national parks. By adding
“solely,” Congress made clear that the exemption granted
was not from such generally applicable regulations. In-
stead, it was from rules applying only in national parks—
i.e., the newly looming Park Service rules. Congress thus
ensured that inholdings would emerge from ANILCA not
worse off—but also not better off—than before.9
——————
   9 The Park Service points to one provision of ANILCA that (it says)

contemplates application of its rules to inholdings; but as suggested in
the text that provision really envisions other agencies’ regulations.
Section 1301(b)(7) requires the Service to create for each system unit a
land management plan that includes (among other things) a description
of “privately owned areas” within the unit, the activities carried out
there, and the “methods (such as cooperative agreements and issuance
or enforcement of regulations)” for limiting those activities if appropri-
ate. 16 U. S. C. §3191(b)(7). Nothing in that section “directs the Park
Service” itself to issue or enforce regulations, as the Service now ar-
gues. See Brief for Respondents 30–31. Instead, the Service satisfies
all its obligations under the provision by reporting on the panoply of
federal and state statutes and regulations that apply to any non-public
land (whether or not in a park). And indeed, the Service’s management
plans have taken exactly that form. See, e.g., Dept. of Interior, Nat.
Park Serv., Kobuk Valley National Park: Land Protection Plan 123–124
(1986) (noting that “[w]hile [Park Service] regulations do not generally
apply to private lands in the park (Section 103, ANILCA),” the regula-
tions “that do apply” include those issued under “the Alaska Anadro-
mous Fish Act, the Endangered Species Act, the Clean Water and
Clean Air acts, and the Protection of Wetlands, to name a few”); Dept.
of Interior, Nat. Park Serv., Noatak National Preserve: Land Protection
                     Cite as: 587 U. S. ____ (2019)       25

                         Opinion of the Court

   The legislative history (for those who consider it) con-
firms, with unusual clarity, all we have said so far. The
Senate Report notes that state, Native, and private lands
in the new Alaskan parks would be subject to “[f]ederal
laws and regulations of general applicability,” such as “the
Clean Air Act, the Water Pollution Control Act, [and] U. S.
Army Corps of Engineers wetlands regulations.” S. Rep.
No. 96–413, p. 303 (1980). But that would not be so of
regulations applying only to parks. The Senate Report
states:
     “Those private lands, and those public lands owned by
     the State of Alaska or a subordinate political entity,
     are not to be construed as subject to the management
     regulations which may be adopted to manage and
     administer any national conservation system unit
     which is adjacent to, or surrounds, the private or non-
     Federal public lands.” Ibid.
The sponsor of Section 103(c) in the House of Representa-
tives described that provision’s effect in similar terms.
The section was designed, he observed, to ensure that
ANILCA’s new boundary lines would “not in any way
change the status” of the state, Native, and private lands
placed within them. 125 Cong. Rec. 11158 (1979) (state-
ment of Rep. Seiberling). Those lands, he continued, “are
not parts of th[e system] unit and are not subject to regu-
lations which are applied” by virtue of being “part of the
unit.” Ibid. In short, whatever the new map might sug-
gest, they are not subject to regulation as parkland.
   We thus arrive again at the conclusion that the Park
Service may not prevent John Sturgeon from driving his
hovercraft on the Nation River. We held in an earlier part
of this opinion that the Nation is not public land. See
supra, at 12–15. And here we hold that it cannot be regu-
——————
Plan 138–139, 142 (1986) (similar).
26                       STURGEON v. FROST

                          Opinion of the Court

lated as if it were. Park Service regulations—like the
hovercraft rule—do not apply to non-public lands in Alas-
ka even when those lands lie within national parks. Sec-
tion 103(c) “deem[s]” those lands outside the parks and in
so doing deprives the Service of regulatory authority.
                              IV
   Yet the Park Service makes one last plea—for some kind
of special rule relating to Alaskan navigable waters. Even
suppose, the argument runs, that those waters do not
count as “public lands.” And even assume that Section
103(c) strips the Service of power to regulate most non-
public lands. Still, the Service avers—invoking “the over-
all statutory scheme”—that ANILCA must at least allow it
to regulate navigable waters. Brief for Respondents 40;
see id., at 40–45; Tr. of Oral Arg. 42 (ANILCA’s regulatory
restrictions were “not about navigable waters”); id., at 63–
64 (similar). Here, the Service points to ANILCA’s general
statement of purpose, which lists (among many other
things) the “protect[ion] and preserv[ation]” of “rivers.” 16
U. S. C. §3101(b). Similarly, the Service notes that the
statements of purpose associated with particular system
units refer to “protect[ing]” named rivers there. E.g.,
§410hh–1(1). And the Service highlights several statutory
sections that in some way speak to its ability to regulate
motorboating and fishing within the new units. See
§§3121, 3170, 3201, 3203(b), 3204.10 According to the
——————
   10 The Park Service also points to a separate title of ANILCA, which

raises issues outside the scope of this case. Title VI designates 26
named rivers in Alaska as “wild and scenic rivers,” to be “administered
by the Secretary” under the (nationwide) Wild and Scenic Rivers Act,
94 Stat. 2412–2413. According to the Service, those special designa-
tions (and associated management instructions) enable it to “adminis-
ter the [specified] rivers pursuant to its general statutory authorities”—
notwithstanding anything in Section 103(c). Brief for Respondents 42–
43. But the Nation River, all agree, is not a “wild and scenic river.” We
may therefore leave for another day the interplay between Section
                       Cite as: 587 U. S. ____ (2019)     27

                           Opinion of the Court

Service, all of those provisions show that “ANILCA pre-
serves [its] authority to regulate conduct on navigable
waters” in national parks. Brief for Respondents 42.
   But ANILCA does not readily allow the decoupling of
navigable waters from other non-federally owned areas in
Alaskan national parks for regulatory (or, indeed, any
other) purposes. Section 103(c), as we have described,
speaks of “lands (as such term is defined in th[e] Act).” 16
U. S. C. §3103(c); see supra, at 9. The Act, in turn, defines
“land” to mean “lands, waters, and interests therein.”
§3102(1)–(3); see supra, at 9. So according to an express
definition, when ANILCA refers to “lands,” it means wa-
ters (including navigable waters) as well. And that kind of
definition is “virtually conclusive.” A. Scalia & B. Garner,
Reading Law: The Interpretation of Legal Texts 228
(2012); see ibid. (“It is very rare that a defined meaning
can be replaced” or altered). Save for some exceptional
reason, we must read ANILCA as treating identically solid
ground and flowing water. So if the Park Service were
right that it could regulate the Nation River under its
ordinary authorities, then it also could regulate the pri-
vate fields and farms in the surrounding park. And more
to the point, once Section 103(c) is understood to preclude
the regulation of those landed properties, then the same
result follows—“virtually conclusive[ ly]”—for the river.
   And nothing in the few aquatic provisions to which the
Park Service points can flip that strong presumption, for
none conflicts with reading Section 103(c)’s regulatory
exemption to cover non-federal waters. The most substan-
tive of those provisions, as just noted, contemplate some
role for the Service in regulating motorboating and fish-
ing. But contra the Park Service, those sections have
effect under our interpretation because both activities can
occur on federally owned (and thus fully regulable) non-
——————
103(c) and Title VI.
28                  STURGEON v. FROST

                      Opinion of the Court

navigable waters. The other provisions the Service em-
phasizes are statements of purpose, which by their nature
“cannot override [a statute’s] operative language.” Id., at
220. And anyway, our construction leaves the Park Ser-
vice with multiple tools to “protect” rivers in Alaskan
national parks, as those statements anticipate. §3101(b);
§410hh–1(1). The Park Service may at a minimum regu-
late the public lands flanking rivers. It may, additionally,
enter into “cooperative agreements” with the State (which
holds the rivers’ submerged lands) to preserve the rivers
themselves. §3181(j). It may similarly propose that state
or other federal agencies with appropriate jurisdiction
undertake needed regulatory action on those rivers. See
§3191(b)(7); see also Kobuk Valley: Land Protection Plan,
at 118, 121 (recommending that the Alaska Department of
Natural Resources classify navigable parts of the Kobuk
River for preservation efforts). And if all else fails, the
Park Service may invoke Section 103(c)’s third sentence to
buy from Alaska the submerged lands of navigable wa-
ters—and then administer them as public lands. See
§§3103(c), 3192; see also Kobuk Valley: Land Protection
Plan, at 133 (proposing that if Alaska does not adequately
protect the Kobuk River, the Park Service should “seek to
acquire title to th[o]se state lands through exchange”).
  Those authorities, though falling short of the Service’s
usual power to administer navigable waters in system
units, accord with ANILCA’s “repeated[ ] recogni[tion] that
Alaska is different.” Sturgeon I, 577 U. S., at ___ (slip op.,
at 13). ANILCA’s broadly drawn parks include stretches
of some of the State’s most important rivers, such as the
Yukon and Kuskokwim. See Brief for State of Alaska as
Amicus Curiae 12. And rivers function as the roads of
Alaska, to an extent unknown anyplace else in the coun-
try. Over three-quarters of Alaska’s 300 communities live
in regions unconnected to the State’s road system. See id.,
at 11. Residents of those areas include many of Alaska’s
                  Cite as: 587 U. S. ____ (2019)           29

                      Opinion of the Court

poorest citizens, who rely on rivers for access to necessities
like food and fuel. See id., at 11–12. Who knows?—maybe
John Sturgeon could have found a comparable hunting
ground that did not involve traveling by hovercraft
through a national park. But some Alaskans have no such
options. The State’s extreme climate and rugged terrain
make them dependent on rivers to reach a market, a
hospital, or a home. So ANILCA recognized that when it
came to navigable waters—just as to non-federal lands—in
the new parks, Alaska should be “the exception, not the
rule.” Sturgeon I, 577 U. S., at ___ (slip op., at 14). Which
is to say, exempt from the Park Service’s normal regula-
tory authority.
                             V
   ANILCA, like much legislation, was a settlement. The
statute set aside more than a hundred million acres of
Alaska for conservation. In so doing, it enabled the Park
Service to protect—if need be, through expansive regula-
tion—“the national interest in the scenic, natural, cultural
and environmental values on the public lands in Alaska.”
16 U. S. C. §3101(d). But public lands (and waters) was
where it drew the line—or, at any rate, the legal one.
ANILCA changed nothing for all the state, Native, and
private lands (and waters) swept within the new parks’
boundaries. Those lands, of course, remain subject to all
the regulatory powers they were before, exercised by the
EPA, Coast Guard, and the like. But they did not become
subject to new regulation by the happenstance of ending
up within a national park. In those areas, Section 103(c)
makes clear, Park Service administration does not replace
local control. For that reason, park rangers cannot enforce
the Service’s hovercraft rule on the Nation River. And
John Sturgeon can once again drive his hovercraft up that
river to Moose Meadows.
   We accordingly reverse the judgment below and remand
30                STURGEON v. FROST

                   Opinion of the Court

the case for further proceedings consistent with this
opinion.
                                       It is so ordered.
                    Cite as: 587 U. S. ____ (2019)                 1

                     SOTOMAYOR, J., concurring

SUPREME COURT OF THE UNITED STATES
                            _________________

                             No. 17–949
                            _________________


  JOHN STURGEON, PETITIONER v. BERT FROST,
  IN HIS OFFICIAL CAPACITY AS ALASKA
                               REGIONAL DI-
 RECTOR OF THE NATIONAL PARK SERVICE, ET AL.
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
            APPEALS FOR THE NINTH CIRCUIT
                          [March 26, 2019]

   JUSTICE SOTOMAYOR, with whom JUSTICE GINSBURG
joins, concurring.
   Professors have long asked law students to interpret a
hypothetical ordinance that prohibits bringing “a vehicle
into the park.”1 The debate usually centers on what
counts as a “vehicle.” Is a moped forbidden? How about a
baby stroller? In this case, we can all agree that John
Sturgeon’s hovercraft is a vehicle. But now we ask whether
he has brought it “into the park”—and, if not, how a
river’s designation as “outside the park” will affect future
attempts to regulate there.
   The Court decides that the Nation River is not park-
land, and I join the Court’s opinion because it offers a
cogent reading of §103(c) of the Alaska National Interest
Lands Conservation Act (ANILCA), 94 Stat. 2371, 16
U. S. C. §3101 et seq. I write separately to emphasize the
important regulatory pathways that the Court’s decision
leaves open for future exploration.
   The Court holds only that the National Park Service
may not regulate the Nation River as if it were within

——————
  1 See A. Scalia & B. Garner, Reading Law: The Interpretation of Le-

gal Texts 36 (2012); Hart, Positivism and the Separation of Law and
Morals, 71 Harv. L. Rev. 593, 607 (1958).
2                    STURGEON v. FROST

                    SOTOMAYOR, J., concurring

Alaska’s federal park system, not that the Service lacks all
authority over the Nation River. A reading of ANILCA
§103(c) that left the Service with no power whatsoever
over navigable rivers in Alaska’s parks would be unten-
able in light of ANILCA’s other provisions, which state
Congress’ intent that the Service protect those very same
rivers. Congress would not have set out this aim and
simultaneously deprived the Service of all means to carry
out the task.
   Properly interpreted, ANILCA §103(c) cannot nullify
Congress’ purposes in enacting ANILCA. Even though the
Service may not apply its ordinary park rules to nonpublic
areas like the Nation River, two sources of Service author-
ity over navigable rivers remain undisturbed by today’s
decision. First, as a default, the Service may well have
authority to regulate out-of-park, nonpublic areas in the
midst of parklands when doing so is necessary or proper to
protect in-park, public areas—for instance, to ban pollu-
tion of the Nation River if necessary to preserve habitat on
the riverbanks or to ban hovercraft use on that river if
needed to protect adjacent public park areas. Nothing in
ANILCA removes that power. Second, Congress most
likely meant for the Service to retain power to regulate as
parklands a particular subset of navigable rivers desig-
nated as “Wild and Scenic Rivers,” although that particu-
lar authority does not, by its terms, apply to the Nation
River.
   Because the Court does not address these agency au-
thorities, see ante, at 19, n. 5, 26–27, n. 10, I join its opin-
ion. I also wish to emphasize, however, that the Court’s
opinion introduces limitations on—and thus could engen-
der uncertainty regarding—the Service’s authority over
navigable rivers that run through Alaska’s parks. If this
is not what Congress intended, Congress should amend
ANILCA to clarify the scope of the Service’s authority.
                    Cite as: 587 U. S. ____ (2019)                   3

                      SOTOMAYOR, J., concurring

                              I
  Since the National Park System’s creation in 1872, it
has grown to include over 400 historic and recreation
areas encompassing over 84 million acres. 54 U. S. C.
§100101(b)(1)(A); 83 Fed. Reg. 2065 (2018). These areas
provide habitat for 247 threatened or endangered species
and received more than 325 million visitors in 2016 alone.
Id., at 2065–2066.
  The task of protecting this vast park system principally
falls to the Park Service. In the National Park Service
Organic Act (Organic Act), 39 Stat. 535, Congress en-
trusted the Service with regulating to leave the parks “un-
impaired for the enjoyment of future generations.” 54
U. S. C. §100101(a). Congress empowered the agency to
promulgate regulations “necessary or proper” for manag-
ing the Park System, including regulations “concerning
boating and other activities on or relating to water located
within [Park] System units.” §§100751(a), (b). The Ser-
vice has carried out this charge by enacting a wide range
of regulations, including the ban on hovercraft use at
issue. See 36 CFR §2.17(e) (2018).
  Wielding its Organic Act authority, the Service applies
many park rules on federally owned lands and waters it
administers, as well as navigable waters “within the
boundaries of the National Park System.” See 36 CFR
§§1.2(a)(1), (3). The title to lands beneath navigable wa-
ters, even within national parks, typically belongs to the
States.2 Because park boundaries can encompass both
federally and nonfederally owned lands and waters, this
means that some nonfederally owned waters are subject to
Service regulations—at least outside of Alaska. See ante,
at 7–8.
——————
  2 Under the Submerged Lands Act of 1953, each State has “title to

and ownership of the lands beneath [its] navigable waters.” 43 U. S. C.
§1311(a); see ante, at 4, 13.
4                   STURGEON v. FROST

                  SOTOMAYOR, J., concurring

   Against this backdrop, Congress enacted ANILCA. As
the Court explains, ANILCA added millions of acres of
federal land to the National Park System in Alaska and
simultaneously swept around 18 million acres of nonfed-
erally owned lands within the geographic boundary lines
of the new Alaska parks. Ante, at 6–8; see also Sturgeon v.
Frost, 577 U. S. ___, ___–___ (2016) (slip op., at 5–6). In
ANILCA, Congress directed the Service to manage Alas-
ka’s new and expanded parks “as new areas of the Na-
tional Park System” under its Organic Act authority. 94
Stat. 2383, 16 U. S. C. §410hh–2.
   ANILCA reflects Congress’ expectation that the Service
will manage Alaska’s parks with a particular focus on
rivers and river systems. For instance, the agency must
“maintain unimpaired the water habitat” for salmon in
Katmai National Monument, preserve “the natural envi-
ronmental integrity and scenic beauty of . . . rivers” in
Gates of the Arctic National Park, and “maintain the
environmental integrity of the entire Charley River basin,
including streams, lakes and other natural features.”
§§410hh(4)(a), (10); §410hh–1(2); see also §§410hh(1), (6),
(7)(a), (8)(a); §410hh–1(1). Some provisions of ANILCA
direct the Service to regulate boating in Alaska’s park-
lands. See, e.g., §3170(a). Others command the Service to
regulate fishing. See, e.g., §3201. Together, these provi-
sions make clear that Congress must have intended for
the Park Service to have at least some authority over
navigable waters within Alaska’s parks.
   And yet, ANILCA includes one provision that can be
read to throw a wrench into that authority: §103(c). This
provision says that “[o]nly those lands within the bounda-
ries of any conservation system unit which are public
lands (as such term is defined in this Act) shall be deemed
to be included as a portion of such unit.” 16 U. S. C.
§3103(c). Section 103(c) then says that no state, native, or
private lands “shall be subject to the regulations applica-
                      Cite as: 587 U. S. ____ (2019)                     5

                       SOTOMAYOR, J., concurring

ble solely to public lands within such units,” although the
Secretary may acquire those lands and administer them
as part of the unit. Ibid. ANILCA, in turn, defines “public
lands” as nearly all “lands, waters, and interests therein”
in which the United States has title. §§3102(1)–(3). Cru-
cially, Alaska has title to the lands under its navigable
waters. See n. 2, supra. If the Service’s ordinary author-
ity over navigable waters within park boundaries is dimin-
ished in Alaska relative to everywhere else in the United
States, all agree that ANILCA §103(c) is the culprit.
                            II
  Thus we arrive at the crux of this case: How, if at all,
does ANILCA §103(c) circumscribe the Service’s ordinary
authority over navigable rivers within the geographic
boundaries of national parks?
                            A
  I agree with the Court that the Service may not treat
every navigable river in Alaska as legally part of Alaska’s
parks merely because those (nonpublic) rivers flow within
park boundaries.      The majority ably explains why
ANILCA’s text leads to this outcome. See ante, at 16–20.
According to ANILCA §103(c), navigable waters (at least
apart from Wild and Scenic Rivers) must be treated as
waters outside of park units for legal purposes. Thus they
may not be “subject to the regulations applicable solely to
public lands within such units.” 16 U. S. C. §3103(c).3
——————
   3 Notably, the Park Service did not argue—nor does the Court’s opin-

ion address—whether navigable waters may qualify as “public lands”
because the United States has title to some interest other than an
interest in reserved water rights. See §§3102(1)–(3). In particular, the
United States did not press the argument that the Federal Government
functionally holds title to the requisite interest because of the naviga-
tional servitude. See, e.g., Kaiser Aetna v. United States, 444 U. S. 164,
177 (1979) (“The navigational servitude . . . gives rise to an authority in
the Government to assure that [navigable] streams retain their capac-
6                       STURGEON v. FROST

                      SOTOMAYOR, J., concurring

  This principle is all that is required to resolve Stur-
geon’s case. The hovercraft rule applies only inside park
boundaries. 36 CFR §1.2(a) (“regulations contained in this
chapter apply to all persons entering, using, visiting, or
otherwise within . . . [w]aters subject to the jurisdiction of
the United States located within the boundaries of the
National Park System”). The Nation River is, for legal
purposes, outside of park boundaries. The hovercraft rule
therefore does not apply on the Nation River.
                               B
  Critically, although the Court decides today that the
Service may not regulate the Nation River “as part of the
park,” ante, at 16, the Court does not hold that ANILCA
§103(c) strips the Service of all authority to protect navi-
gable waters in Alaska. For good reason. It would be
absurd to think that Congress intended for the Service to
preserve Alaska’s rivers, but left it without any tools to
do so.
  Imagine if all Service regulations could apply in Alas-
ka’s parklands only up to the banks of navigable rivers,
and the Service lacked any authority whatsoever over the
rivers themselves. If Jane Smith were to stand on the
public bank of the Nation River, bag of trash in hand,
Service rules could prohibit her from discarding the trash
on the riverbank. See 36 CFR §2.14(a)(1). The rules also
could bar her from intentionally disturbing wildlife breed-
ing activities, §2.2(a)(2), making unreasonably loud noises,
§2.12(a)(1)(ii), and introducing wildlife into the park eco-
system, §2.1(a)(2). But reading ANILCA §103(c) to bar
any Park Service regulation of navigable waters would
——————
ity to serve as continuous highways for the purpose of navigation in
interstate commerce”); United States v. Rands, 389 U. S. 121, 123
(1967) (“This power to regulate navigation confers upon the United
States a ‘dominant servitude’ ”); 43 U. S. C. §1314 (providing that the
United States retains the navigational servitude in navigable waters).
                     Cite as: 587 U. S. ____ (2019)                     7

                       SOTOMAYOR, J., concurring

permit Jane to evade those rules entirely if she were to
wade into the river or paddle along the bank in a canoe.
She could toss her trash bag in the water and amp up her
speakers with impunity. Under this reading, the Park
Service would be powerless to stop her. Jane’s actions
would likely harm flora and fauna on the banks of the
river, which are public areas inside park boundaries.
Jane’s trash also could drift from a navigable (and thus
out-of-park, nonpublic) stretch of the Nation River into a
nonnavigable (and thus in-park, public) stretch of the
same river.4 So much for the Service’s duty to maintain
the “environmental integrity” of the Charley River basin
“in its undeveloped natural condition,” 16 U. S. C.
§410hh(10).
   How can the Service adequately protect Alaska’s rivers
if it cannot regulate? What is more, how can it maintain
nearby park areas, such as riverbanks or nonnavigable
park waters downstream, if it has no power to check the
contamination of navigable waters? To achieve Congress’
stated goals in creating Alaska’s parks, the Service must
have some authority to protect navigable rivers within
those parks.5



——————
  4 The navigability of a river is determined “on a segment-by-segment

basis.” PPL Montana, LLC v. Montana, 565 U. S. 576, 593 (2012); see
also id., at 594.
  5 Even if the Service cannot regulate the rivers itself, the majority

says that the agency can enter into “cooperative agreements” with
Alaska to regulate the rivers, 16 U. S. C. §3181(j), propose that state or
other federal agencies take action to protect the rivers, §3191(b)(7), or
buy the submerged lands from Alaska and then regulate them,
§§3103(c), 3192. See ante, at 28. But Congress made the Service
directly responsible for protecting Alaska’s parks and park resources.
The Service cannot carry out its duty to “manag[e]” the park areas,
see §410hh, if it is estopped from promulgating necessary rules and
regulations.
8                       STURGEON v. FROST

                       SOTOMAYOR, J., concurring

                             C
  Thankfully, today’s decision does not leave the Service
without any authority over the Nation River and other
rivers like it. Even though most navigable rivers in Alaska
are not public parklands, Congress has left at least two
avenues for the Service to achieve ANILCA’s purposes.
Neither is addressed by the Court’s decision.
                              1
   First, the Court expressly does not decide whether the
Service may regulate navigable waters running through
Alaska’s parks as an adjunct to its authority over the
parks themselves. See ante, 19, n. 5.6 In my view, the
Service likely retains power over navigable rivers that run
through Alaska’s parks when that power is necessary to
protect Alaska’s parklands.
   The Service’s default ability to regulate comes from the
Organic Act. That Act gives the Service general authority
to promulgate all regulations “necessary or proper” for
managing park units, including power to regulate activi-
ties “on or relating to water located within [Park] System
units.” 54 U. S. C. §§100751(a), (b) (emphasis added).
Nothing in the text of the Organic Act suggests that the
Service is powerless over out-of-park areas in the midst of
public parklands, like the Nation River.
   This brings us back to Jane, this time canoeing down
the Nation River with a gallon of toxic insecticide onboard.

——————
   6 The Court’s interpretation prohibits the Service only from applying

its usual, in-park rules to out-of-park areas. See, e.g., ante, at 16
(nonpublic lands “may not be regulated as part of the park”); ante, at 18
(Section 103(c)’s exclusion “exempt[s] non-public lands . . . from the
Park Service’s ordinary regulatory authority”); ante, at 19 (the areas
“are no longer subject to the Service’s power over ‘System units’ and the
‘water located within’ them”); ante, at 22 (rejecting suggestion that
inholdings can be “regulated as parklands”); ante, at 25 (the inholdings
“are not subject to regulation as parkland”).
                  Cite as: 587 U. S. ____ (2019)             9

                   SOTOMAYOR, J., concurring

If Jane spills the insecticide into the river, the effects will
surely reach the riverbanks—public areas within the
park’s legal boundaries. An antipollution rule tailored to
apply to the Nation River as it runs through the park thus
could well be “necessary or proper” to manage the park-
lands on either side of the river, even though the river
itself is not legally a part of the park. §100751(a). And if
the pollution is likely to harm nonnavigable stretches of
the river downstream—public waters that are “within” the
park for legal purposes—the ban also could be authorized
because it specifically concerns “activities . . . relating to
water located within [Park] System units.” §100751(b).
Similar reasoning could justify a range of Service regula-
tions, giving the Service substantial authority over navi-
gable rivers inside geographic park boundaries in order to
protect the parklands through which they flow.
   Assuming that the Service has such authority over out-
of-park areas pursuant to its Organic Act, nothing in
ANILCA §103(c) takes it away. That section’s first sen-
tence explains that nonpublic lands are not part of Alas-
ka’s park units. See 16 U. S. C. §3103(c); supra, at 4–5.
The second sentence then emphasizes that the Service
cannot regulate nonpublic lands as if they were part of the
park. Together, these sentences mean that the Service
loses its authority to apply normal park rules to nonpublic
lands, and instead can apply only those rules that it can
justify by reference to the needs of other, public lands. For
instance, the Service is unlikely to have power to apply
rules against abandoning property, 36 CFR §2.22(a), or
trespassing, §2.31(a)(1), to nonpublic lands amid park-
lands because doing so would have little or no impact on
neighboring public areas within the legal boundaries of
the park. But a Service regulation tailored to apply to
nonparklands in order to protect sensitive surrounding
parklands—like a rule against putting a toxic substance in
the Nation River to stop harms to the riverbanks—would
10                      STURGEON v. FROST

                      SOTOMAYOR, J., concurring

present a different question. Such a regulation could be
consistent with the Service’s limited Organic Act authority
over out-of-park areas, and it would not run afoul of
ANILCA because it would not be applicable to public
lands.
   The Service’s out-of-park authority is not at issue in this
case given that the hovercraft regulation applies only
within park boundaries, see ante, at 19, n. 5. Hovercraft
can be unsightly, be loud, and disturb sensitive ecosystems
within the park. See 48 Fed. Reg. 30258 (1983) (“The
Service has determined that hovercraft should be prohib-
ited because they provide virtually unlimited access to
park areas and introduce a mechanical mode of transpor-
tation into locations where the intrusion of motorized
equipment by sight or sound is generally inappropriate”).
If the Service were to choose to apply its hovercraft ban to
the Nation River, the agency could justify doing so in
certain designated areas to protect a particular sensitivity
in a surrounding (public) park area, including some habi-
tats on the banks of the Nation River.
                               2
  The Court also leaves open a second way for the Service
to protect navigable rivers. Because the Nation River is
not a designated Wild and Scenic River, the Court ex-
pressly does not decide the extent of the Service’s power over
such designated rivers. Ante, at 26–27, n. 10. If ANILCA
§103(c) is to be harmonized with the remainder of the
statute, the Service must possess authority to regulate
fully, as parklands, at least that subset of rivers.7
——————
   7 This authority would supplement, not replace, the Service’s author-

ity over out-of-park navigable rivers, because the Service’s authority
over the Wild and Scenic Rivers alone cannot explain all of ANILCA’s
express references to protecting Alaskan rivers. For instance, ANILCA
states Congress’ expectation that the Service will manage the Kobuk
River in Kobuk Valley National Park. See 16 U. S. C. §410hh(6). That
                     Cite as: 587 U. S. ____ (2019)                  11

                      SOTOMAYOR, J., concurring

  The Wild and Scenic Rivers Act, 16 U. S. C. §1271 et
seq., established a system of rivers that “possess outstand-
ingly remarkable scenic, recreational, geologic, fish and
wildlife, historic, cultural, or other similar values.” §1271.
Congress created the system to “preserv[e]” designated
rivers “in free-flowing condition.” Ibid. Rivers can become
part of the system if they are designated by an Act of
Congress. §1273(a)(i).
  ANILCA designated 26 Alaskan rivers as components of
this system, more than doubling the mileage of the rivers
in the system at the time. 16 U. S. C. §1274; S. Johnson &
L. Comay, CRS Report for Congress, The National Wild
and Scenic Rivers System: A Brief Overview 1 (2015); see
§1281(c). ANILCA, in turn, expressly defines the Alaskan
park system as including “any unit in Alaska of the . . .
National Wild and Scenic Rivers Systems.” §3102(4).
  Although ANILCA §103(c) generally has the effect of
removing navigable waters from the legal boundaries of
Alaska’s parks, Congress’ highly specific definition of the
Wild and Scenic Rivers as a portion of Alaska’s park sys-
tem overrides ANILCA §103(c)’s general carveout. “Gen-
eral language of a statutory provision . . . will not be held
to apply to a matter specifically dealt with in another part
of the same enactment.” D. Ginsberg & Sons, Inc. v. Pop-
kin, 285 U. S. 204, 208 (1932). To make sense of ANILCA
§103(c) within the context of the rest of ANILCA, the
Service should retain full authority to regulate the Wild
and Scenic Rivers as parklands.


——————
portion of the river is not designated as a Wild and Scenic River, see
§1274, but the Bureau of Land Management has found it to be naviga-
ble, see Dept. of Interior, Nat. Park Service, Kobuk Valley National
Park: General Management Plan 65 (1987). The Service therefore must
have another source of authority over the river if the statute’s purpose
provision is not to be deprived of meaning.
12                   STURGEON v. FROST

                   SOTOMAYOR, J., concurring

                          *      *    *
   One final note warrants mention. Although I join the
Court’s opinion, I recognize that today’s decision creates
uncertainty concerning the extent of Service authority
over navigable waters in Alaska’s parks. Courts ultimately
may affirm some of the Service’s authority over out-of-
park areas and Wild and Scenic Rivers. But that author-
ity may be more circumscribed than the special needs of
the parks require. This would not only make it impossible
for the Service to fulfill Congress’ charge to preserve riv-
ers, made plain in ANILCA itself, but also threaten the
Service’s ability to fulfill its broader duty to protect all of
the parklands through which the rivers flow. See, e.g., 16
U. S. C. §410hh(6) (Kobuk Valley National Park “shall be
managed . . . [t]o maintain the environmental integrity of
the natural features of the Kobuk River Valley, including
the Kobuk, Salmon, and other rivers”). Many of Alaska’s
navigable rivers course directly through the heart of pro-
tected parks, monuments, and preserves. A decision that
leaves the Service with no authority, or only highly con-
strained authority, over those rivers would undercut
Congress’ clear expectations in enacting ANILCA and
could have exceedingly damaging consequences.
   In light of the explicit instructions throughout ANILCA
that the Service must regulate and protect rivers in
Alaska, I am convinced that Congress intended the Service
to possess meaningful authority over those rivers. If I am
correct, Congress can and should clarify the broad scope of
the Service’s authority over Alaska’s navigable waters.
