                   FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

RIVER RUNNERS FOR WILDERNESS;            
ROCK THE EARTH; WILDERNESS
WATCH; LIVING RIVERS, nonprofit
corporations,
                Plaintiffs-Appellants,
                  v.
STEPHEN P. MARTIN, in his official
capacity as Superintendent of
Grand Canyon National Park;
DIRECTOR OF THE NATIONAL PARK                  No. 08-15112
SERVICE; NATIONAL PARK SERVICE;
KENNETH L. SALAZAR, in his
official capacity as Secretary of
                                                D.C. No.
                                             CV-06-00894-DGC
the U.S. Department of the                      OPINION
Interior; UNITED STATES
DEPARTMENT OF THE INTERIOR;
DIANE J. HUMETEWA; ERIC H.
HOLDER JR.,
              Defendants-Appellees,
GRAND CANYON RIVER OUTFITTERS
ASSOCIATION; GRAND CANYON
PRIVATE BOATERS ASSOCIATION,
             Defendant-Intervenors-
                            Appellees.
                                         
        Appeal from the United States District Court
                 for the District of Arizona
        David G. Campbell, District Judge, Presiding

                   Argued and Submitted
          June 10, 2009—San Francisco, California

                              1785
1786              RIVER RUNNERS v. MARTIN
                  Filed February 1, 2010

       Before: Procter Hug, Jr., Betty B. Fletcher and
          Michael Daly Hawkins, Circuit Judges.

                    Per Curiam Opinion
                   RIVER RUNNERS v. MARTIN                1789




                         COUNSEL

Julia A. Olson, Wild Earth Advocates, Eugene, Oregon, and
Matthew K. Bishop, Western Environmental Law Center,
Helena, Montana, for the plaintiffs-appellants.

Charles R. Scott, Attorney, United States Department of Jus-
tice, Washington, D.C., for Federal appellees.

Sam Kalen, Van Ness Feldman, PC, Washington, D.C., for
defendant-intervenor-appellee Grand Canyon River Outfitters
Association.

Lori Potter, Kaplan Kirsch & Rockwell LLP, Denver, Colo-
rado, for defendant-intervenor-appellee Grand Canyon Private
Boaters Association.


                         OPINION

PER CURIAM:

   This case concerns the National Park Service’s decision to
permit the continued use of motorized rafts and support
equipment in Grand Canyon National Park. Plaintiffs contend
that such motorized activities impair the wilderness character
of the Canyon and that the Park Service’s decision violates its
management policies and various federal statutes. Plaintiffs
asked the District Court to set aside the decision under the
Administrative Procedure Act (“APA”). For reasons
1790                   RIVER RUNNERS v. MARTIN
explained in this opinion, Plaintiffs have not satisfied the high
threshold required to set aside federal agency actions under
the APA.1

I.       Background.

  Grand Canyon National Park (“Park”) was established by
Congress in 1919 and expanded in 1975. The Park consists of
more than 1.2 million acres located on the southern end of the
Colorado Plateau in Arizona.

   The Park includes a 277-mile stretch of the Colorado River
referred to in this order as the “Colorado River Corridor” or
the “Corridor.” The Park Service regulates the Colorado River
Corridor through a periodically-revised Colorado River Man-
agement Plan (“Management Plan”). In November of 2005,
the Park Service issued a Final Environmental Impact State-
ment (“FEIS”) for the 2006 Management Plan. On February
17, 2006, the Park Service issued a Record of Decision
(“ROD”) that adopted and approved the 2006 Management
Plan. The 2006 Management Plan permits the continued use
of motorized rafts, generators, and helicopters in the Colorado
River Corridor.

  Plaintiffs River Runners for Wilderness, Rock the Earth,
Wilderness Watch, and Living Rivers constitute a coalition of
organizations committed to protecting and restoring the Grand
Canyon’s wilderness character and unique natural resources
and ensuring fair access to it. Plaintiffs filed this action
against the Park Service and various individual Defendants.2
     1
     The wording of Judge Campbell’s carefully crafted district court opin-
ion with its detailed factual discussion and thorough analysis, with which
we agree, has been utilized in this opinion.
   2
     The named individual Defendants included Joseph F. Alston, superin-
tendent of the Park; Fran Mainella, director of the Park Service; Gale Nor-
ton, Secretary of the United States Department of the Interior; the
Department of the Interior; Paul K. Charlton, former United States Attor-
ney for Arizona; and Alberto R. Gonzales, former Attorney General.
                   RIVER RUNNERS v. MARTIN                  1791
The district court subsequently permitted two private organi-
zations to intervene in the action — Grand Canyon River Out-
fitters Association, which consists of commercial operators of
motorized and non-motorized rafts in the Colorado River Cor-
ridor, and Grand Canyon Private Boaters Association, which
consists of private rafters and kayakers of the Corridor (col-
lectively, “Intervenors”).

   Following exchanges of information and compilation of the
administrative record, Plaintiffs, Defendants, and Intervenors
all filed motions for summary judgment. The district court
held oral argument on October 26, 2007.

  A.   Park Service Management of the Colorado River
       Corridor.

   The waters of the Colorado River originate in the moun-
tains of Colorado, Wyoming, and Utah and run 1,450 miles
to the Gulf of California. The Colorado is the longest and
largest river in the Southwestern United States. Once in the
Grand Canyon, the river flows some 4,000 to 6,000 feet
below the rim of the Canyon through cliffs, spires, pyramids,
and successive escarpments of colored stone. Access to the
bottom of the Grand Canyon can be gained only by hiking,
riding mules, or floating the river. Those floating the river
typically do so in motor-powered rubber rafts, oar- or paddle-
powered rubber rafts, oar-powered dories, or kayaks. Floating
the river through the Grand Canyon is considered one of
America’s great outdoor adventures and includes some of the
largest white-water rapids in the United States.

   Use of the Colorado River Corridor increased substantially
after Glen Canyon Dam was completed in 1963 and produced
a relatively steady flow through the Canyon. Because of this
increased use, the Park Service initiated a series of river plan-
ning and management efforts, culminating in a December
1972 River Use Plan. The plan concluded that “motorized
craft should be phased-out of use in the Grand Canyon.” The
1792                  RIVER RUNNERS v. MARTIN
plan also concluded that 89,000 commercial user days and
7,600 non-commercial user days would be allocated for the
1973 season, but that commercial use would be scaled down
to 55,000 user days by 1977.3 A 1973 Draft Environmental
Impact Statement concluded that “[t]he use of motors . . .
should be eliminated as soon as possible from the river envi-
ronment” and that “[t]he propose[d] elimination of motorized
trips will . . . hav[e] a positive environmental impact.”

   The Park Service initiated a Colorado River Research Pro-
gram in 1974 to examine, among other things, the impact of
motorized activities on the river. In September of 1977, the
Park Service issued a document suggesting that “the use of
motors is contrary to established health and safety standards”
and again opining that the “use of motorized craft should be
eliminated.” The document noted that “[n]on-motorized travel
is more compatible with wilderness experience” and that
“[m]otor noise levels may have adverse effects on pilot per-
formance, resulting in potential safety hazards.” The Park Ser-
vice was unable, however, to document any difference in
numbers and degree of injuries between the two types of craft.

   The Park Service released the first Management Plan in
December of 1979. Use of motorized watercraft between Lees
Ferry and Separation Canyon was to be phased out over a
five-year period. The 1979 Management Plan stated that such
a phase-out was consistent with the “objective of the [1976]
Master Plan[,] corresponded with the park wilderness propos-
al,” and was “based on the extensive Colorado River Research
project for the Grand Canyon[.]” The Management Plan
increased the allocated commercial user days from 89,000 per
  3
   “A ‘user day’ is calculated by multiplying the number of passengers by
the number of days. (A ‘day’ is defined as any portion of a 24-hour day.)
For example, if the [permit] holder has two clients on a two day trip, this
would equal four user days.” National Park Service, How a Commercial
Use Authorization Works, https://cms.imr.nps.gov/bibe/parkmgmt/cua-
operations.htm (last updated June 9, 2007).
                   RIVER RUNNERS v. MARTIN                1793
year to 115,500 and increased the allocated non-commercial
user days from 7,600 to 54,450. In September 1980, the Park
Service proposed that the Colorado River Corridor be desig-
nated as “potential wilderness” and, once motorboat use was
phased-out, as “wilderness.”

   Congress countermanded the 1979 Management Plan in a
1981 appropriations bill for the Department of the Interior.
The bill prohibited the use of appropriated funds “for the
implementation of any management plan for the Colorado
River within the [Park] which reduces the number of user
days or passenger-launches for commercial motorized water-
craft excursions[.]” Members of Congress sent a letter to the
Park Service expressing their “wish that the [1979 Manage-
ment Plan] be amended to accommodate the 1978 level and
pattern of commercial, motorized watercraft access while at
the same time protecting the increased non-commercial allo-
cation which the plan provides.” The Park Service subse-
quently revised the 1979 Management Plan to “retain[ ]
motorized use and the increase in user-days that had been
intended as compensation for the phase-out of motors, result-
ing in more motorized use of the river.”

   The Park Service issued a second Management Plan in
1989. The 1989 Management Plan was similar to the revised
1979 Management Plan. It included the same allocation of
user days for commercial and non-commercial boaters, but
increased the number of non-commercial launches.

  B.   The 2006 Management Plan.

  Planning for the 2006 Management Plan began in 1997
with the solicitation of public comments and a series of public
workshops in Oregon, Utah, and Arizona. After this process
was suspended and restarted following the filing of two law-
suits, the Park Service published in the Federal Register, on
June 13, 2002, a notice of intent to prepare an environmental
impact statement for a revised Management Plan. Seven addi-
1794               RIVER RUNNERS v. MARTIN
tional public meetings and stakeholder workshops were held
in Colorado, Utah, Arizona, Nevada, Maryland, and Califor-
nia. More than one thousand people attended the meetings and
the Park Service received more than 13,000 written submis-
sions.

   In the Fall of 2004, the Park Service released for public
review a Draft Environmental Impact Statement (“DEIS”) for
the revised Management Plan. The DEIS presented eight
alternatives (Alternatives A-H) for managing the river from
Lees Ferry to Diamond Creek, a stretch of 226 miles (referred
to in this order as the “Lees Ferry Segment”) and five alterna-
tives (Alternatives 1-5) for managing the river from Diamond
Creek to Lake Mead, a stretch of 51 miles (referred to in this
order as the “Lower Gorge.”) The alternatives included
motorized and non-motorized options. Because of the com-
plexity of the DEIS and the level of public interest, the Park
Service extended the standard 90-day comment period for one
additional month. The Park Service also hosted public meet-
ings in Colorado, Utah, Washington, D.C., Nevada, Arizona,
and California. The Park Service received some 10,000 writ-
ten submissions, including approximately 6,000 substantive
and 30,000 non-substantive comments on the DEIS. The Park
Service coded, organized, analyzed, and responded to the sub-
stantive comments, and modified the DEIS where it felt modi-
fications were warranted.

  The Park Service received comments from a coalition of
groups representing both commercial and non-commercial
boaters of the Colorado River Corridor — groups often at
odds with each other on issues of river management. The
coalition included Intervenors, American Whitewater, and
Grand Canyon River Runners Association. The coalition sup-
ported equal allocation of river time between commercial and
non-commercial boaters and the continued authorization of
appropriate levels of motorized use.

  In November 2005, the Park Service issued the three-
volume Final Environmental Impact Statement. The FEIS
                    RIVER RUNNERS v. MARTIN                   1795
addressed the same alternatives discussed in the DEIS, with
some modifications to Alternatives H and 4, and expressed a
preference for Modified Alternative H for the Lees Ferry Seg-
ment and Modified Alternative 4 for the Lower Gorge. The
selected alternatives permitted the use of motorized rafts, gen-
erators for emergencies and inflating rafts, and helicopters to
make passenger exchanges at the Whitmore helipad. As noted
above, in February 2006, the Park Service issued a ROD that
formally adopted Modified Alternatives H and 4 for the 2006
Management Plan.

II.   The District Court’s Task.

   Plaintiffs argue that the 2006 Management Plan is unlawful
and should be set aside. The court’s task is not to make its
own judgment about whether motorized rafts should be
allowed in the Colorado River Corridor. Congress has dele-
gated that responsibility to the Park Service. The court’s
responsibility is narrower: to determine whether the Park Ser-
vice’s 2006 Management Plan comports with the require-
ments of the APA, 5 U.S.C. § 701 et seq.

   The APA does not allow the court to overturn an agency
decision because it disagrees with the decision or with the
agency’s conclusions about environmental impacts. Vt. Yan-
kee Nuclear Power Corp. v. Natural Res. Def. Council, Inc.,
435 U.S. 519, 555 (1978) (citing Kleppe v. Sierra Club, 427
U.S. 390, 410 n.21 (1976)). An agency’s decision may be set
aside only if it is “arbitrary, capricious, an abuse of discretion,
or otherwise not in accordance with law.” 5 U.S.C.
§ 706(2)(A). The standard is deferential. The court “may not
substitute its judgment for that of the agency concerning the
wisdom or prudence of [the agency’s] action.” Or. Envtl.
Council v. Kunzman, 817 F.2d 484, 492 (9th Cir. 1987).

  In conducting an APA review, the court must determine
whether the agency’s decision is “founded on a rational con-
nection between the facts found and the choices made . . . and
1796               RIVER RUNNERS v. MARTIN
whether [the agency] has committed a clear error of judg-
ment.” Ariz. Cattle Growers’ Ass’n v. U.S. Fish & Wildlife,
273 F.3d 1229, 1243 (9th Cir. 2001). “The [agency’s] action
. . . need only be a reasonable, not the best or most reasonable,
decision.” Nat’l Wildlife Fed. v. Burford, 871 F.2d 849, 855
(9th Cir. 1989).

   Plaintiffs assert that the 2006 Management Plan is arbitrary
and capricious under the APA because it violates the Park
Service’s own policies, the National Park Service Conces-
sions Management and Improvement Act (“Concessions
Act”), and the National Park Service Organic Act (“Organic
Act”). Each of these arguments will be addressed separately,
and this opinion is precedential only as to those issues
appealed.

III.   Compliance with Park Service Policies.

  A.    Enforceability of the Policies.

   Even though Congress has never acted on the Park Ser-
vice’s recommendation to designate a substantial portion of
the Park as wilderness, Plaintiffs claim that the Park Service’s
own policies give rise to a legally binding obligation to main-
tain the wilderness character of the Park. Plaintiffs claim that
the Park Service has breached this legal duty by authorizing
the continued use of motorized activities in the 2006 Manage-
ment Plan. Defendants and Intervenors argue that the Park
Service policies do not have the force and effect of law and
therefore may not be enforced against the Park Service in this
action.

   In their motion for summary judgment, Plaintiffs identified
three policies that allegedly create binding obligations on the
Park Service: the 1976 Master Plan, the 1995 General Man-
agement Plan, and the 2001 Park Service Management Poli-
cies (the “2001 Policies”). Two of these arguments — the
1976 Master Plan and the 1995 General Management Plan —
                   RIVER RUNNERS v. MARTIN                    1797
are not on appeal. Plaintiffs instead focus on the 2001 Poli-
cies, arguing that they are binding because they are written in
mandatory language, were mentioned in the Federal Register,
and have been found binding in S. Utah Wilderness Alliance
v. Nat’l Park Serv., 387 F. Supp. 2d 1178 (D. Utah 2005).

   In United States v. Fifty-Three (53) Eclectus Parrots, 685
F.2d 1131 (9th Cir. 1982), we established a two-part test for
determining when agency pronouncements have the force and
effect of law:

    To have the force and effect of law, enforceable
    against an agency in federal court, the agency pro-
    nouncement must (1) prescribe substantive rules —
    not interpretive rules, general statements of policy or
    rules of agency organization, procedure or practice
    — and (2) conform to certain procedural require-
    ments. To satisfy the first requirement the rule must
    be legislative in nature, affecting individual rights
    and obligations; to satisfy the second, it must have
    been promulgated pursuant to a specific statutory
    grant of authority and in conformance with the pro-
    cedural requirements imposed by Congress.

Id. at 1136 (internal quotes and citations omitted).

   [1] The 2001 Policies fail the first part of the Eclectus Par-
rots test because they do not purport to prescribe substantive
rules. As the United States Court of Appeals for the District
of Columbia Circuit recently held with respect to these very
Policies: “While the text of the Policies on occasion uses
mandatory language, such as ‘will’ and ‘must,’ the document
as a whole does not read as a set of rules. It lacks precision
in its directives, and there is no indication of how the enumer-
ated policies are to be prioritized.” The Wilderness Soc’y v.
Norton, 434 F.3d 584, 595 (D.C. Cir. 2006).

   [2] The text of the 2001 Policies makes clear that they are
intended only to provide guidance within the Park Service,
1798                RIVER RUNNERS v. MARTIN
not to establish rights in the public generally. The Introduc-
tion describes the Policies as a “basic Service-wide policy
document,” as a “guidance document[ ],” and as a statement
of policy “designed to provide [Park Service] management
and staff with clear and continuously updated information . . .
that will help them manage parks and programs effectively.”
That the 2001 Policies are not intended to have the same force
as binding Park Service regulations is made clear by the Intro-
duction’s explanation that existing, formally-promulgated
Park Service regulations will trump inconsistent provisions in
the 2001 Policies until such time as the regulations “are for-
mally revised through the rulemaking procedure[.]”

   Equally significant, the Introduction to the 2001 Policies
provides that Park Service management can choose to waive
or modify the Policies: “Adherence to policy is mandatory
unless specifically waived or modified in writing by the Sec-
retary, the Assistant Secretary, or the Director.” “Waivers and
modifications will be considered on a case-by-case basis,” the
Policies explain. Needless to say, policy statements that may
be waived or modified by an agency can hardly be said to
have the binding force of law. As the D.C. Circuit noted, “this
language does not evidence an intent on the part of the agency
to limit its discretion and create enforceable rights. Rather, the
agency’s top administrators clearly reserved for themselves
unlimited discretion to order and reorder all management pri-
orities.” Wilderness Soc’y, 434 F.3d at 596.

   Nor do the 2001 Policies purport to create substantive indi-
vidual rights or obligations for persons or entities outside the
Park Service. The Policies set forth priorities, practices, and
procedures to be followed by Park Service personnel in
administering the national park system. In the words of Eclec-
tus Parrots, they are “interpretive rules, general statements of
policy or rules of agency organization, procedure or prac-
tice[.]” 685 F.2d at 1136 (quotes and citations omitted). See
also United States v. Alameda Gateway Ltd., 213 F.3d 1161,
1168 (9th Cir. 2000) (agency rule did not have the force or
                   RIVER RUNNERS v. MARTIN                  1799
effect of law in part because “[i]t was not intended to create
substantive rights in third parties”); Moore v. Apfel, 216 F.3d
864, 868-69 (9th Cir. 2000) (agency provision did not satisfy
the Eclectus Parrots test, as it “creates no substantive rights”
and instead “provides [agency] staff with internal proce-
dures”); Chrysler Corp. v. Brown, 441 U.S. 281, 302 (1979)
(whether an agency pronouncement affects individual rights
and obligations “is an important touchstone for distinguishing
those rules that may be binding or have the force of law”)
(internal quotation marks and citation omitted).

   The 2001 Policies also fail the second part of the Eclectus
Parrots test. The APA requires that “publication or service of
a substantive rule shall be made not less than 30 days before
its effective date.” 5 U.S.C. § 553(d). The 2001 Policies were
not published in the Federal Register. The Park Service did
publish a notice of the availability of a draft of the 2001 Poli-
cies and a notice of new policy, but never published the 2001
Policies themselves. See 65 Fed. Reg. 2984 (Jan. 19, 2000);
65 Fed. Reg. 56003 (Sept. 15, 2000). What is more important,
the Policies were never published in the Code of Federal Reg-
ulations. This suggests that the Park Service did not intend to
announce substantive rules enforceable by third parties in fed-
eral court. See W. Radio Servs. Co., Inc. v. Espy, 79 F.3d 896,
901 (9th Cir. 1996) (stating, in its determination that two
agency documents did not satisfy the Eclectus Parrots test,
that “[n]either [document] is published in the Federal Register
or the Code of Federal Regulations”). The D.C. Circuit found
this lack of publication “particularly noteworthy” in conclud-
ing that the 2001 Policies are not substantive law. Wilderness
Soc’y, 434 F.3d at 595; see also Brock v. Cathedral Bluffs
Shale Oil Co., 796 F.2d 533, 539 (D.C. Cir. 1986) (“The real
dividing point between regulations and general statements of
policy is publication in the Code of Federal Regulations[.]”).

  This conclusion is bolstered by the Park Service’s own
characterization of the 2001 Policies. In its Federal Register
announcement that a draft of the 2001 Policies was available
1800               RIVER RUNNERS v. MARTIN
for public comment, the Park Service explained that “park
superintendents, planners, and other [Park Service] employees
use management policies as a reference source when making
decisions that will affect units of the national park system.”
65 Fed. Reg. 2984 (Jan. 19, 2000). A “reference source,” of
course, is not the same as binding substantive law.

   [3] In sum, the 2001 Policies are not enforceable against
the Park Service in this action. The Policies do not prescribe
substantive rules, nor were they promulgated in conformance
with the procedures of the APA. Eclectus Parrots, 685 F.2d
at 1136. The Court therefore may not set aside the 2006 Man-
agement Plan because it fails to comply with portions of the
2001 Policies requiring the Park Service to treat the Colorado
River Corridor as wilderness or potential wilderness.

  B.   Plaintiffs’ Chevron Cases.

   Plaintiffs argue that the lack of formal rulemaking does not
prevent the 2001 Policies from having the force and effect of
law. For support, Plaintiffs rely primarily on United States v.
Mead Corp., 533 U.S. 218 (2001), and S. Utah Wilderness
Alliance, 387 F.Supp.2d 1178. Plaintiffs in Mead challenged
a tariff ruling by the United States Customs Service. Plaintiffs
in S. Utah Wilderness Alliance challenged a decision by the
Park Service to ban motorized vehicles in a portion of Can-
yonlands National Park. In both cases the courts were
required to decide whether the agency decisions were entitled
to deference under Chevron U.S.A. Inc. v. Natural Resources
Defense Council, Inc., 467 U.S. 837 (1984).

   The Supreme Court explained Chevron deference in this
manner: when Congress has expressed an expectation that an
agency will speak with the force of law and resolve ambigui-
ties or fill gaps in statutory law, “a reviewing court has no
business rejecting an agency’s exercise of its generally con-
ferred authority . . . simply because the agency’s chosen reso-
lution seems unwise, but is obligated to accept the agency’s
                   RIVER RUNNERS v. MARTIN                 1801
position if Congress has not previously spoken to the point at
issue and the agency’s interpretation is reasonable[.]” Mead,
533 U.S. at 229 (citations omitted). In short, Courts are not to
interfere with reasonable agency decisions rendered within
areas where Congress has authorized the agencies to act.

   [4] Among other considerations, a court applying the Chev-
ron doctrine asks whether an agency decision is intended by
Congress to have the force of law. The Supreme Court noted
in Mead that the existence of formal notice-and-comment
rulemaking is a strong indicator of such authority. The
Supreme Court went on to explain, however, that “as signifi-
cant as notice-and-comment rulemaking is in pointing to
Chevron authority, the want of that procedure here does not
decide the case, for we have sometimes found reasons for
Chevron deference even when no such administrative formal-
ity was required and none was afforded[.]” Id. at 230-31. The
District Court in S. Utah Wilderness Alliance relied on this
language and found that Chevron deference was due the Park
Service’s decision to ban motorized vehicles in Canyonlands
even though the decision was based on the 2001 Policies that
were not adopted through formal notice-and-comment rule-
making. 387 F. Supp. 2d at 1187-88. Plaintiffs rely on this
holding and the above-quoted language from Mead to argue
that the same 2001 Policies should have the force and effect
of law in this case.

   There is a difference, however, between application of the
Chevron doctrine in SUWA and the question to be decided in
this case. The plaintiffs in SUWA argued that the 2001 Poli-
cies were not entitled to deference and that a decision based
on them should be set aside. The District Court relied on the
Chevron doctrine to conclude that the 2001 Policies provided
a sound basis for deference to the Park Service — a shield for
the agency’s decision concerning the proper administration of
Canyonlands National Park. Plaintiffs in this case seek an
opposite result — to use the same 2001 Policies as a sword
1802               RIVER RUNNERS v. MARTIN
to set aside Park Service decisions concerning the proper
administration of Grand Canyon National Park.

   [5] Chevron analysis does not control this case. Whether
an agency’s decision falls within the scope of activity
intended by Congress to resolve ambiguities or fill gaps in the
governing statutes and therefore is entitled to deference in the
courts is a different question than whether an agency’s deci-
sion becomes binding law that gives outside parties the right
to enforce the decision against the agency in court. The first
question asks whether the agency has acted within the realm
and with the expertise Congress intended. The second focuses
on the substance and form of the agency’s action and asks
whether the agency intended to promulgate binding law for
itself and the outside world. This case presents the second
question — a question to be decided under Eclectus Parrots.
As explained above, the 2001 Policies are not enforceable
against the Park Service under Eclectus Parrots.

  C.   The Policies Do Not Render the 2006 Management
       Plan Arbitrary and Capricious.

   [6] Citing Ecology Center, Inc. v. Austin, 430 F.3d 1057
(9th Cir. 2005), and related cases, Plaintiffs alternatively
argue that the 2006 Management Plan is arbitrary and capri-
cious even if the 2001 Policies do not have the force and
effect of law. We held in Ecology Center that the Forest Ser-
vice could not disregard a non-binding soil standard when the
Forest Service’s own environmental impact statement pur-
ported to comply with the standard. To disregard the standard,
we held, would render the environmental impact statement
misleading and unlawful. Id. at 1069. Plaintiffs argue that
because the FEIS and ROD purport to follow the 2001 Poli-
cies and the 1995 General Management Plan, but in fact fail
to do so, they are arbitrary and capricious. We do not agree.

  Plaintiffs base their argument on the fact that the Colorado
River Corridor has been classified by the Park Service as
                      RIVER RUNNERS v. MARTIN                      1803
potential wilderness. The 2001 Policies provide the following
guidance with respect to the management of potential wilder-
ness areas:

      The National Park Service will take no action that
      would diminish the wilderness suitability of an area
      possessing wilderness characteristics until the legis-
      lative process of wilderness designation has been
      completed. . . . This policy also applies to potential
      wilderness, requiring it to be managed as wilderness
      to the extent that existing non-conforming conditions
      allow. The National Park Service will seek to
      remove from potential wilderness the temporary,
      non-conforming conditions that preclude wilderness
      designation.

2001 Policies § 6.3.1 (SAR 016136-37). The FEIS makes this
same commitment with respect to the Colorado River Corri-
dor. See FEIS Vol. I at 234.

   [7] The language of § 6.3.1 makes clear that the Park Ser-
vice is required to manage potential wilderness areas as actual
wilderness only “to the extent that existing non-conforming
conditions allow.” This language does not require the Park
Service immediately to remove existing non-conforming uses
— in this case, motorized rafts. It requires the Park Service
to manage the Colorado River Corridor as wilderness to the
extent possible given the existing use of motors. In light of
this clear provision, the court cannot conclude that the 2006
Management Plan is arbitrary and capricious for failing to
remove motorized uses in the Colorado River Corridor immedi-
ately.4
  4
   Nor did Plaintiffs appear to believe that immediate removal was
required when they submitted written comments on the DEIS. Plaintiffs
did not assert that the 2001 Policies required the immediate removal of
motorized uses, but instead endorsed a plan to “phas[e] out motorized use
over a reasonable time period not to exceed 10 years.” AR 050222.
1804                   RIVER RUNNERS v. MARTIN
   Section 6.3.1 further states that the Park Service “will seek
to remove from potential wilderness the temporary, non-
conforming conditions that preclude wilderness designation.”
2001 Policies § 6.3.1 (SAR 016137). Seasonal uses of motors
on the river do not preclude wilderness designation. Plaintiffs
do not contend that such uses work any permanent change on
the Corridor that would preclude later wilderness treatment.
Seasonal float trips are not like the construction of a road or
other physical improvements that might disqualify an area for
wilderness designation in the future. Motorized float trips can
readily be eliminated if Congress decides that the Corridor
should be designated as wilderness. The FEIS concludes that
the use of motors in the Corridor “is only a temporary or tran-
sient disturbance of wilderness values” and “does not perma-
nently impact wilderness resources or permanently denigrate
wilderness values.” FEIS, Vol. I at 17; see also AR 093108-
19 (discussion of limited effect of motorized uses on soils),
AR 093051 (same for water quality), AR 093083-84 (same
for air quality), AR 093132-33 (same for natural soundscape).5

   We note, additionally, that federal agencies are entitled to
some leeway when interpreting their own policies and regula-
tions. Stinson v. United States, 508 U.S. 36, 45 (1993)
(“provided an agency’s interpretation of its own regulations
does not violate the Constitution or a federal statute, it must
be given controlling weight unless it is plainly erroneous or
inconsistent with the regulation.”). When that leeway is added
to the Management Plan’s general consistency with the 2001
Policies, the court cannot conclude that the policies, even if
not enforceable in court, render the Management Plan arbi-
trary and capricious.
  5
    During oral argument, Plaintiffs asserted that § 6.4.3.3 of the 2001 Pol-
icies, which precludes motors in “wilderness” areas, trumps § 6.3.1. It
appears to the Court, however, that § 6.3.1 is the more relevant provision
because it applies specifically to areas “possessing wilderness characteris-
tics” that have not yet been designated as wilderness by Congress — pre-
cisely the circumstance of the Colorado River Corridor.
                   RIVER RUNNERS v. MARTIN                1805
   [8] Finally, Plaintiffs argue that the 2006 Management Plan
is arbitrary and capricious because it contradicts earlier Park
Service decisions to phase out motorized boating in the Colo-
rado River Corridor. As noted above, the 1979 Management
Plan called for motorized watercraft between Lees Ferry and
Separation Canyon to be phased out over a five-year period.
SAR 005244. The Court cannot conclude, however, that the
2006 Management Plan is arbitrary and capricious solely
because it differs from earlier Park Service decisions. Part of
the discretion granted to federal agencies is the freedom to
change positions. As the Supreme Court has explained, “[a]n
agency’s view of what is in the public interest may change,
either with or without a change in circumstances. But an
agency changing its course must supply a reasoned analysis.”
Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto Ins. Co.,
463 U.S. 29, 57 (1983) (quotation omitted). The question
posed by this lawsuit, therefore, is not whether the 2006 Man-
agement Plan differs from past Park Service decisions, but
whether it is arbitrary and capricious in light of facts in the
administrative record and the reasoning of the FEIS. For rea-
sons explained herein, the court finds the 2006 Management
Plan sufficiently reasonable to pass APA muster.

IV.   The Concessions Act.

   [9] Plaintiffs contend that the 2006 Management Plan is
arbitrary and capricious because it fails to comply with the
requirements of the Concessions Act. The Act governs the
granting of commercial concessions within the National Park
System. “To make visits to national parks more enjoyable for
the public, Congress authorized [the Park Service] to grant
privileges, leases, and permits for the use of land for the
accommodation of visitors. Such privileges, leases, and per-
mits have become embodied in national parks concession con-
tracts.” Nat’l Park Hospitality Ass’n v. Dep’t of the Interior,
538 U.S. 803, 805-806 (2003). The specific provision of the
Act relied on by Plaintiffs articulates a Congressional “poli-
cy” for the granting of concessions:
1806              RIVER RUNNERS v. MARTIN
       It is the policy of the Congress that the develop-
    ment of public accommodations, facilities, and ser-
    vices in units of the National Park System shall be
    limited to those accommodations, facilities, and ser-
    vices that —

      (1) are necessary and appropriate for public use
    and enjoyment of the unit of the National Park Sys-
    tem in which they are located; and

       (2) are consistent to the highest practicable degree
    with the preservation and conservation of the
    resources and values of the unit.

16 U.S.C. § 5951(b).

   Plaintiffs claim that the 2006 Management Plan is arbitrary
and capricious because the Park Service never determined that
the types and levels of motorized uses authorized by the Man-
agement Plan are necessary and appropriate for public use and
consistent with the Park’s resources and values. Before
addressing this argument, we must address the legal standard
that governs review of a Concessions Act claim.

  A.   Legal Standard Under the Concessions Act.

   In support of their Concessions Act argument, Plaintiffs
rely heavily on High Sierra Hikers Ass’n v. Blackwell, 390
F.3d 630 (9th Cir. 2004), a case in which we struck down the
Forest Service’s grant of permits to commercial packstock
operators in the Ansel Adams and John Muir Wilderness
Areas of California. The court held that the Forest Service
must make a finding that “the number of permits granted was
no more than was necessary to achieve the goals of the Act.”
Id. at 647. Plaintiffs argue that Blackwell requires a similar
Park Service finding for the number of motorized raft trips
permitted in the 2006 Management Plan.
                   RIVER RUNNERS v. MARTIN                 1807
   It is significant, however, that the court in Blackwell was
applying the Wilderness Act, not the Concessions Act. The
Wilderness Act places strict limitations on the use of lands
formally designated by Congress as wilderness. With narrow
exceptions, the Wilderness Act prohibits commercial enter-
prises, permanent roads, and motorized vehicles in wilderness
areas. 16 U.S.C. § 1133(c). Federal agencies are obligated to
manage such areas to preserve their wilderness character. Id.
at § 1133(b). We explained in Blackwell that the Forest Ser-
vice’s obligation to limit commercial packstock permits
“flows directly out of the agency’s obligation under the Wil-
derness Act to protect and preserve wilderness areas.” 390
F.3d at 647. It was this “ultimate interest” and “overarching
purpose” of the Wilderness Act — to protect the Ansel
Adams and John Muir Wilderness Areas from degradation —
that led the Ninth Circuit to hold that the packstock permit
decision violated “the Forest Service’s statutory responsibili-
ty.” Id. at 647-48.

   This case, by contrast, does not concern a wilderness area.
Congress has never acted on the Park Service’s recommenda-
tion that portions of the Park be formally designated as wil-
derness. The Park Service, therefore, is not under the same
“statutory responsibility” that applied to the Forest Service in
Blackwell. The court must look to the Concessions Act, not
the Wilderness Act, for the governing legal standard.

   In Wilderness Preservation Fund v. Kleppe, 608 F.2d 1250
(9th Cir. 1972), we decided a case under 16 U.S.C. § 20, the
statutory predecessor to the Concessions Act. See City of
Sausalito v. O’Neill, 386 F.3d 1198, 1204 (9th Cir. 2004)
(Kleppe decided under predecessor to Concessions Act); Pub.
L. 105-391, 1123 Stat. 3515 (16 U.S.C. § 20 superceded by
16 U.S.C. § 5951). The predecessor statute, like the Conces-
sions Act, stated a Congressional “policy” that commercial
concessions in national parks should be “limited to those that
are necessary and appropriate for public use and enjoyment of
the national park area in which they are located.” Kleppe, 608
1808               RIVER RUNNERS v. MARTIN
F.2d at 1253. In rejecting a challenge under this policy to the
Park Service’s allocation of rafting permits in the Colorado
River Corridor, Kleppe recognized the “administrative discre-
tion” granted the Park Service and invoked “a judicial pre-
sumption favoring the validity of administrative actions.” Id.
at 1254.

   [10] This more deferential standard appears to be war-
ranted. The Park Service is charged with administering almost
400 national parks. See National Park Service, About Us,
http://www.nps.gov/aboutus/index.htm (last visited October
22, 2009). The Concessions Act does not impose strict wilder-
ness requirements on those parks, but instead articulates a pol-
icy that calls for the Park Service to balance the interests of
public use and resource preservation. 16 U.S.C. § 5951(b).
The Park Service’s balancing of those interests over the broad
range and diverse circumstances of hundreds of national parks
is appropriately accorded the kind of deference recognized in
Kleppe. The Court concludes that the deferential approach of
Kleppe, rather than the statutory application of the Wilderness
Act in Blackwell, should govern this case.

  B.   The 2006 Management Plan and the Concessions
       Act.

   Plaintiffs first contend that the Park Service failed entirely
to determine that the types and levels of commercial services
authorized by the 2006 Management Plan are necessary and
appropriate. We disagree. The Park Service made the follow-
ing determinations:

    Since many visitors who wish to raft on the Colo-
    rado River through Grand Canyon possess neither
    the equipment nor the skill to successfully navigate
    the rapids and other hazards of the river, the [Park
    Service] has determined that it is necessary and
    appropriate for the public use and enjoyment of the
    park to provide for experienced and professional
                     RIVER RUNNERS v. MARTIN                1809
    river guides who can provide such skills and equip-
    ment.

                              ***

    [S]ervices provided by commercial outfitters, which
    enable thousands of people to experience the river in
    a relatively primitive and unconfined manner and
    setting (when many of them otherwise would be
    unable to do so), are necessary to realize the recre-
    ational or other wilderness purposes of the park.

FEIS Vol. I at 19.

   Plaintiffs argue that although the Park Service may have
found commercial outfitters to be necessary and appropriate
generally, it never made such a finding for motorized com-
mercial services. Again we disagree. The ROD specifically
states that “[d]etermination of the types and levels of commer-
cial services that are necessary and appropriate for the Colo-
rado River through Grand Canyon National Park were
determined through [the FEIS].” ROD at 6 (emphasis added).
Among the eight management alternatives considered by the
Park Service in the DEIS and FEIS were two that did not
authorize any motorized uses in the Colorado River Corridor
(Alternatives B and C). After evaluating these alternatives, the
Park Service found that they “violated the basic premise of
this planning effort; that of reducing congestion, crowding
and impacts without reducing access of visitors to the Colo-
rado River[.]” FEIS Vol. III at 373. “As demonstrated by the
Park Service’s analysis of the no-motor alternatives, a deci-
sion by the Park Service to eliminate the motorized trip option
would cause a dramatic reduction in the public availability of
professionally outfitted river trips[.]” Id. at 87. The Park Ser-
vice explained that “continued authorization of motorized use
for recreational river trips in the [Park] is essential . . . to
meeting the . . . management objectives” for the 2006 Man-
agement Plan. Id. Thus, the Park Service quite clearly con-
1810               RIVER RUNNERS v. MARTIN
cluded that motorized commercial services were “necessary
and appropriate for public use and enjoyment” of the Corri-
dor. 16 U.S.C. § 5951(b).

   Plaintiffs contend that even if the Park Service found that
motorized services were necessary and appropriate, it made
no determination as to the amount of such services that are
necessary, and therefore failed to “limit” motorized uses to
those that are necessary and appropriate as required by the
Congressional policy statement of the Concessions Act. It is
true that the FEIS and ROD do not contain a specific discus-
sion of the amount of motorized traffic found necessary and
appropriate for public use and enjoyment of the Corridor. But
the absence of such a specific discussion does not necessarily
require the agency’s action to be overturned. “While [a court]
may not supply a reasoned basis for the agency’s action that
the agency itself has not given, [the court] will uphold a deci-
sion of less than ideal clarity if the agency’s path may reason-
ably be discerned.” Bowman Transp., Inc. v. Arkansas-Best
Freight Sys., Inc., 419 U.S. 281, 285 (1974) (citations omit-
ted). The Park Service’s consideration of the amount of
motorized traffic required in the Colorado River Corridor can
reasonably be discerned from the FEIS.

   The 1989 Management Plan established use levels that
were still in effect when the 2006 Management Plan planning
process began. Among the alternatives considered in the
DEIS and FEIS was a “no-action alternative” — an alterna-
tive that would have left the 1989 levels in place. This alterna-
tive, designated in the FEIS as Alternative A, would continue
to allocate 113,083 user days to commercial operators (74,260
motorized and 38,823 non-motorized) and 58,048 user days to
non-commercial users. FEIS Vol. I at 45. Alternative B would
have eliminated all motorized traffic on the river and allo-
cated 97,694 user days to commercial operators and 74,523 to
non-commercial. Id. at 47. Alternative C also would have
eliminated all motorized trips, but would have increased com-
mercial user days to 166,814 and non-commercial to 115,783,
                   RIVER RUNNERS v. MARTIN                  1811
presumably to accommodate sufficient numbers of visitors
with the slower non-motorized trips. Id. at 49. Alternatives D,
E, F, and G would have permitted motorized uses, but varied
the amounts for commercial and non-commercial traffic. Id.
at 51-57. The levels of motorized user days for Alternatives
D, E, F, and G would have been 70,104, 76,913, 83,076, and
76,913, respectively. Id.

   User days were not the only variables evaluated by the Park
Service. The FEIS also considered months without motors on
the river, trip lengths, trip lengths during various parts of the
year, group sizes, numbers of launches, numbers of passen-
gers, and helicopter exchanges at the Whitmore helipad. Id. at
61. The Park Service evaluated these alternatives against
environmental, social, and park-management factors includ-
ing impacts on soils, water, air, soundscape, caves, vegetation,
terrestrial life, aquatic resources, special status species, cul-
tural resources, visitor experience, socio-economic resources,
park management and operations, adjacent lands, and wilder-
ness character. Id. at 61-65.

   The Park Service ultimately concluded that Alternatives B
and C — the non-motor alternatives — would not meet the
agency’s objective of providing “a diverse range of quality
recreational opportunities for visitors to experience and
understand the environmental interrelationships, resources,
and values of Grand Canyon National Park” because of the
significantly reduced number of visitors who could experi-
ence the Colorado River Corridor. Id. at 71; see FEIS Vol. II
at 626-27, 630-31. The Park Service evaluated a range of
motorized use times in the other alternatives and, after consid-
ering all factors and variables, selected Modified Alternative
H. That Alternative included specific allocations for motor-
ized and non-motorized uses: a total of 115,500 commercial
user days consisting of 76,913 motorized and 38,587 non-
motorized, and an estimated 113,486 non-commercial user
days. FEIS Vol. I at 60.
1812                  RIVER RUNNERS v. MARTIN
   Modified Alternative H reduced the amount of motorized
traffic in the Colorado River Corridor and the months within
which it can occur, while significantly increasing the traffic
for non-commercial uses. The time period during which it
prohibited motorized uses in the Corridor each year is Sep-
tember 16 through March 31 — 3.5 months longer than under
the 1989 Management Plan. FEIS Vol. I at 61. Modified
Alternative H also reduced motorized commercial launches
from 473 per year to 429 per year, and total motorized passen-
gers from 14,487 to 13,177. Id. at 45, 60. Maximum group
sizes for commercial motor excursions were also reduced
from 43 to 32. Id. at 61. Commercial user days were held
essentially level at 115,500, while non-commercial user days
were more than doubled to an estimated 113,486. Id. at 60.6

   [11] In sum, the Park Service’s decision concerning the
amount of motorized trips on the river was made after consid-
ering competing alternatives and a significant number of vari-
ables. The Park Service chose an alternative that reduced
motorized uses from current levels. The court is satisfied that
the Park Service, as stated in the ROD, determined the “type
and level” of traffic on the river that was “necessary and
appropriate,” including the type and level of motorized uses.
ROD at 6.

   Plaintiffs argue that even if the Park Service made such a
determination, the determination was arbitrary and capricious.
As noted above, however, the decision occurred only after an
extensive analysis of various alternatives. Defendants have
identified a number of factors in the Administrative Record
  6
     The Park Service considered five alternatives for the Lower Gorge,
including a no-action alternative (Alternative 1), but the Lower Gorge
issues differed from those in the Lees Ferry Segment. Plaintiffs have spent
little time addressing Lower Gorge issues in this case. The Lower Gorge
management is complicated by the existence of Hualapai tribal lands and
Hualapai River Runner day trips. After undertaking an analysis of five
alternatives, the Park Service selected Alternative 4, which eliminated up-
river jet boat tours. FEIS Vol. I at xiii.
                    RIVER RUNNERS v. MARTIN                  1813
that support the Park Service’s decision to allow motorized
traffic to continue. First, because motorized trips take less
time to complete (10 days as opposed to 16 days for non-
motorized trips), substantially more people can see the Park
each year from the river if motorized trips continue. FEIS
Vol. I at 33-34; Vol. III at 87-88, 328-29. Second, motorized
trips are frequently chartered for special-needs groups, educa-
tional classes, family reunions, or to support kayak or other
paddle trips. Third, because of their increased mobility,
motorized trips help alleviate overcrowding at popular camp-
sites and attractions in the Corridor. FEIS Vol. I at 33-34;
Vol. III at 302. Fourth, some individuals feel safer when trav-
eling in motorized rafts. FEIS Vol. III at 312-313. In addition,
studies performed as part of the DEIS found that visitors are
able to experience the river as wilderness in the presence of
motorized uses and that those who took motorized trips were
significantly more likely to stress safety and trip length as the
most important factors in the choosing the type of trip they
took.

   [12] Given the “judicial presumption favoring the validity
of administrative actions” and the “administrative discretion”
granted the Park Service under the Concessions Act, Kleppe,
608 F.2d at 1254, the court cannot conclude that the agency
acted arbitrarily and capriciously when it found that the Modi-
fied Alternative H levels of motorized uses were “necessary
and appropriate for public use and enjoyment” of the Colo-
rado River Corridor. 16 U.S.C. § 5951(b). The question is not
whether this court agrees with the Park Service’s decision, but
whether it is reasonably supported by the Administrative
Record. In light of the DEIS and FEIS analysis outlined
above, we conclude that it is.

   Plaintiffs spend little time addressing the other policy state-
ment of the Concessions Act — that the necessary and appro-
priate public uses should be “consistent to the highest
practicable degree with the preservation and conservation of
the resources and values of the unit.” 16 U.S.C. § 5951(b).
1814                RIVER RUNNERS v. MARTIN
Read in isolation, this policy could eliminate all public uses
of the Colorado River Corridor, motorized and non-
motorized, because preservation of the natural resources of
the Corridor would be accomplished to the “highest practica-
ble degree” by eliminating all human interference. This is not
what Congress intended. The Concessions Act, after all,
authorizes the Park Service to permit commercial concessions
in national parks. Rather, this policy must be achieved in light
of the policy’s preceding requirement — that uses be limited
to those necessary and appropriate for public use of the parks.
Once those necessary uses are identified, they must be man-
aged to the highest practicable degree to preserve the
resources and values of the Park.

   We are satisfied that the Park Service did not act arbitrarily
and capriciously when it concluded that Modified Alternative
H was consistent to the highest practicable degree with pre-
serving the resources and values of the Corridor. As noted
above, the DEIS and FEIS evaluated Modified Alternative H
and other alternatives against a large number of environmen-
tal factors. With the exception of the effects of motors on the
soundscape of the Park, Plaintiffs do not challenge this evalu-
ation. With respect to the effects on soundscape, we conclude
that the Park Service did not act arbitrarily and capriciously.

V.     The Organic Act.

   [13] The Organic Act provides that the Park Service “shall
promote and regulate the use of . . . national parks . . . in such
manner and by such means as will leave them unimpaired for
the enjoyment of future generations.” 16 U.S.C. § 1. The Act
also provides that “[n]o natural curiosities, wonders, or
objects of interest shall be leased, rented, or granted to anyone
on such terms as to interfere with free access to them by the
public[.]” 16 U.S.C. § 3. Plaintiffs contend that the 2006
Management Plan is arbitrary and capricious because it per-
mits commercial boaters to use the river at levels that interfere
with free access by the public, and because it concludes that
                      RIVER RUNNERS v. MARTIN                        1815
motorized uses do not impair the natural soundscape of the
Park.

  A.    Free Access.

   [14] Plaintiffs argue that the allocation of river access
between commercial and non-commercial users is inequitable
and thus limits the free access of members of the public. As
noted above, however, the Park Service has significantly
increased the access of non-commercial users. The 2006 Man-
agement Plan allocates 115,500 user days to commercial users
and an estimated 113,486 user days to non-commercial users.
See FEIS Vol. I at ix.7 This is essentially the same allocation
commercial users received under the 1989 Management Plan,
but a substantial increase from the 58,048 user days that non-
commercial boaters received under the 1989 plan. Stated in
different terms, the allocation of river time between commer-
cial and non-commercial user days changed from 66.5% com-
mercial and 33.5% non-commercial under the 1989
Management Plan, to 50.4% commercial and 49.6% non-
commercial under the 2006 Management Plan. The 2006
Management Plan also reduced the number of launches and
passengers for commercial users while nearly doubling both
categories for non-commercial users. FEIS Vol. I at 45, 60. It
is noteworthy that neither GCROA, which consists of com-
mercial river users, nor GCPBA, which consists of non-
commercial users, agree with Plaintiffs. Both organizations
  7
   Plaintiffs argue that user days are not a fair measure of use. While the
Park Service has stated that “[d]aily launches are probably the most
important use measure for measuring impacts to visitor use and experi-
ence,” it also has noted that “[t]he daily number of people launching
would probably provide similar information[.]” FEIS Vol. III at 55. The
court finds that user days — a factor of the number of people that launch
and the number of days the trip lasts — is a reasonable basis for analysis.
The Ninth Circuit used the same measure in Kleppe. See 608 F.2d 1250.
1816                    RIVER RUNNERS v. MARTIN
contend that the Park Service’s allocation of user days is reason-
able.8

   [15] Plaintiffs argue that non-commercial users are required
to wait for permits to run the river — sometimes for 10 or
more years — while clients of commercial rafting companies
usually can book a trip within one year. They also assert that
the current allocation favors the wealthy who can afford com-
mercial trips, and they criticize the Park Service for not con-
ducting a demand study that would have revealed the most
equitable allocation. The court cannot conclude on this basis,
however, that the Management Plan is arbitrary and capri-
cious. The 2006 Management Plan significantly revised the
system for private boaters to obtain permits by establishing a
lottery system that is weighted to favor those who have not
received a permit in previous years. ROD at 20. Moreover,
surveys show that 61% of private boaters have floated the
Colorado River Corridor before, while only 20% of commer-
cial boaters were on repeat trips. The existence of a waiting
list therefore does not necessarily show that more private
boaters than commercial customers are awaiting their first
river trip. Finally, experts advised the Park Service that a
demand study would cost more than $2 million and likely
would be of limited value. FEIS Vol. III at 177.
   8
     Plaintiffs complain that a substantial portion of the additional non-
commercial days are in the winter, and that the Park Service acted without
evidence that boaters would use the river in the winter. Defendants note
that the 2006 Management Plan increases non-commercial user days in all
seasons of the year. The FEIS also notes that “there is interest in trips dur-
ing the winter . . . . [W]inter trips offer greater opportunities for quiet and
solitude compared to other times of the year. The less crowded nature of
winter months enhances wildlife viewing and cooler daytime temperatures
are conducive to off-river hiking.” FEIS Vol. I at 34 (emphasis omitted).
Ninety percent of available winter dates were used between 1998 and
2002 — 100% when they were made available six months in advance. AR
107920, 109498. The court concludes that the Park Service had a reason-
able basis for concluding that winter trips would be used by non-
commercial boaters.
                      RIVER RUNNERS v. MARTIN                        1817
  More generally, Plaintiffs tend to characterize the dispute
as one between commercial companies and private citizens.
This is not the true nature of the issue:

      Throughout these proceedings [plaintiff] has per-
      sisted in viewing the dispute as one between the rec-
      reational users of the river and the commercial
      operators, whose use is for profit. It asserts that by
      giving a firm allocation to the commercial operators
      to the disadvantage of those who wish to run the
      river on their own the Service is commercializing the
      park. [Plaintiff] ignores the fact that the commercial
      operators, as concessioners of the [Park] Service,
      undertake a public function to provide services that
      the [Park Service] deems desirable for those visiting
      the area. The basic face-off is not between the com-
      mercial operators and the non-commercial users, but
      between those who can make the run without profes-
      sional assistance and those who cannot.

Kleppe, 608 F.2d at 1253-54 (internal citations omitted).

  As noted above, a coalition of commercial and private
boater organizations submitted joint comments to the Park
Service that supported an equal allocation of river time
between commercial and non-commercial users on an annual
basis. These users of the river apparently did not believe that
such a system would interfere with free access.9
  9
   In support of their argument, Plaintiffs submitted the affidavit of Don-
ald W. Walls. Dkt. #71-2. Dr. Walls opines that an equal allocation
between commercial and non-commercial boaters cannot be determined to
be fair in the absence of a demand study, and that a lottery system that
applies to all users would be more fair. As noted above, however, a panel
of experts advised the Park Service in January of 2003 that a demand
study was likely to cost $2 million and be of limited use. FEIS Vol. III at
177. Dr. Walls does not address this advice and therefore does not provide
a basis for concluding that the Park Service acted arbitrarily and capri-
ciously when it decided not to conduct such a study. Moreover, although
1818                   RIVER RUNNERS v. MARTIN
  B.    Impairment of the Natural Soundscape.

   Plaintiffs make several arguments in support of their claim
that the Park Service acted arbitrarily and capriciously when
it concluded that motorized uses of the Corridor do not impair
the natural soundscape of the Park within the meaning of the
Organic Act. These arguments are unpersuasive.

   First, Plaintiffs contend that the Park Service used the
wrong baseline — that it compared motor-generated sounds
to the noise of the Corridor with aircraft flying overhead,
rather than comparing motorized noises to the natural quiet of
the Park. This argument is incorrect. The Park Service com-
pared periods of noise from river traffic (motorized and non-
motorized) to periods when there was no noise. FEIS Vol. II
at 348-87. The Park Service also evaluated the length of
“noise-free intervals” when motorized traffic was in the Park.
See, e.g., id. at 386.

   Plaintiffs next contend that the Park Service failed to con-
sider the cumulative effects of noise from river traffic. This
also is incorrect. After comparing river traffic noise to natural
background sounds, and evaluating noise-free intervals, the
Park Service considered the cumulative effect of such noise
when added to other sounds in the Park such as aircraft over-

Dr. Walls opines that a lottery system would be more fair than the Park
Service’s equal allocation of days between commercial and non-
commercial users, he does not address whether such a system — which
would render the yearly demand for commercial services less predictable
— would permit the continued operation of commercial river runners that
the Park Service has found to be necessary and appropriate. Nor does Dr.
Walls address the fact that a coalition of river users, including commercial
and private users, supported the equal allocation adopted by the Park Ser-
vice, or explain why the Park Service’s consideration of such representa-
tive support was unreasonable. Dr. Walls’ opinion, although a legitimate
point of view, does not persuade the court that the Management Plan is
arbitrary and capricious.
                   RIVER RUNNERS v. MARTIN                   1819
flights. The Park Service then reached the following conclu-
sion:

    Although Modified Alternative H would contribute
    to the overall cumulative effects of noise on the
    park’s natural soundscape, even if all noise from all
    river recreation was eliminated from the park
    (including river-related helicopter flights at Whit-
    more), the cumulative effects of aircraft noise would
    still be adverse, short- to long-term, and major.
    There would still be ‘significant adverse effects’ on
    the natural soundscape due to frequent, periodic and
    noticeable noise from overflights, and ‘substantial
    restoration of natural quiet’ would not be achieved as
    required by Public Law 100-91 and other mandates.

Id. at 387 (emphasis omitted).

   Plaintiffs contend that this cumulative analysis should have
caused the Park Service to eliminate sounds from motorized
river traffic. But if a cumulative analysis were to result in the
elimination of all sounds that can be eliminated by the Park
Service — in this case, all sounds other than aircraft over-
flights, which are not within the jurisdiction of the Park Ser-
vice — then all human activity in the Park would be
eliminated. And still the aircraft overflights would create sub-
stantial and adverse sound effects in the Park. Plaintiffs have
articulated no principled basis upon which the court can con-
clude that the Park Service should have eliminated motorized
noises on the basis of such cumulative analysis, but not other
human-caused noises such as hiking or non-motorized raft
trips. The court cannot conclude that the Park Service acted
arbitrarily and capriciously when it concluded from a
cumulative-effects analysis that motorized river traffic noise
was not the source of serious sound problems in the Park and
that elimination of such noise would not significantly improve
the overall soundscape.
1820                 RIVER RUNNERS v. MARTIN
   Finally, Plaintiffs argue that the Park Service failed to con-
sider earlier environmental impact statements and a number of
studies conducted in the 1970s, some of which found that
river use impacted the soundscape within the Park. The Park
Service relied primarily on studies conducted by noise experts
in 1993 and 2003. FEIS Vol. II at 352-53. These studies
included field acoustic measurements, including sounds from
motorized and non-motorized raft trips. The studies deter-
mined the distance at which motorized rafts could be heard
and the length of time they were audible while traveling
down-river, when measured from fixed points in the Park. Id.
The studies also evaluated the effects of other sounds such as
water flow, wind, wildlife, human voices, helicopters, and air-
craft overflights. Id. The studies provide a reasonable basis
for evaluating sound effects within the Park.

   Plaintiffs argue that the Park Service failed to consider 28
previous studies, but they identify no specific studies for the
court to consider. Nor do Plaintiffs cite any recent studies that
call into question the findings of the 1993 and 2003 studies.
Defendants also note that any studies conducted in the 1970s
would have concerned louder two-stroke engines rather than
the quieter and cleaner four-stroke engines now used in the
Corridor. Finally, the 2003 study specifically considered and
summarized the earlier studies relied on by Plaintiffs.

   [16] Given all of these considerations, the court cannot con-
clude that the Park Service acted arbitrarily and capriciously
when it concluded that motorized uses do not impair the
soundscape of the Park within the meaning of the Organic
Act.

VI.    Conclusion.

  [17] Plaintiffs have failed to establish that the Park Service
acted arbitrarily and capriciously when it adopted the 2006
Management Plan. The court accordingly AFFIRMS the
granting of the summary judgment motions of Defendants and
                 RIVER RUNNERS v. MARTIN            1821
Intervenors and the denial of the summary judgment motion
of Plaintiffs.

  AFFIRMED.
