                FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

CALIFORNIA TROUT,                     
                        Petitioner,
                                           No. 07-73664
              v.
                                         FERC Project No.
FEDERAL ENERGY REGULATORY                    2426-204
COMMISSION,
                    Respondent.
                                      

CALIFORNIA TROUT,                     
                        Petitioner,
                                           No. 07-74494
              v.
                                         FERC Project No.
FEDERAL ENERGY REGULATORY                    2426-206
COMMISSION,
                    Respondent.
                                      

FRIENDS OF THE RIVER,                 
                        Petitioner,        No. 08-71593
              v.
                                         FERC Project No.
                                             2426-208
FEDERAL ENERGY REGULATORY
COMMISSION,                                  OPINION
                    Respondent.
                                      
        On Petition for Review of an Order of the
         Federal Energy Regulatory Commission

                 Argued and Submitted
      February 12, 2009—San Francisco, California

                    Filed July 20, 2009

                           9159
9160               CALIFORNIA TROUT v. FERC
         Before: Ronald M. Gould, Jay S. Bybee, and
          Timothy M. Tymkovich,* Circuit Judges.

                   Opinion by Judge Bybee;
                   Dissent by Judge Gould




   *The Honorable Timothy M. Tymkovich, United States Circuit Judge
for the Tenth Circuit, sitting by designation.
                CALIFORNIA TROUT v. FERC             9163




                       COUNSEL

Daniel P. Selmi (argued), Los Angeles, California, and Amy
J. Bricker, Rachel B. Hooper, and Amanda Garcia, San Fran-
cisco, California, for the petitioners.

Holly E. Cafer, Kathrine Henry (argued), Cynthia Marlette,
and Robert H. Solomon, Washington, D.C., for the respon-
dent.
9164              CALIFORNIA TROUT v. FERC
                          OPINION

BYBEE, Circuit Judge:

    The Supreme Court has long stressed that “the formulation
of procedures [is] basically to be left within the discretion of
the agencies to which Congress [has] confided the responsi-
bility for substantive judgments.” Vt. Yankee Nuclear Power
Corp. v. Natural Res. Def. Council, Inc., 435 U.S. 519,
524-25 (1978). Agencies must have the ability to manage
their own dockets and set reasonable limitations on the pro-
cesses by which interested persons can support or contest pro-
posed actions. In this respect, an agency’s procedural rules
operate much as our own rules of procedure do: we require
litigants to observe the orderly procedures of the court, even
if such rules occasionally bar inattentive or ill-advised parties
from our courtrooms. So long as an agency’s procedural rules
do not afford petitioners less protection than the minimum
mandated by the Administrative Procedure Act (“APA”) and
the Constitution, we are not free to “improperly intrude[ ] into
the agency’s decisionmaking process” and second-guess its
administrative tradeoffs. Id. at 525.

   In this case, petitioners California Trout (“CalTrout”) and
Friends of the River (“FOR”) contend that the Federal Energy
Regulatory Commission (“the Commission”) applied its rule
governing intervention in a license renewal proceeding in an
arbitrary and capricious fashion. Although petitioners have set
forth evidence that their late intervention would not prejudice
the Commission’s proceeding, under the circumstances we
cannot find that the Commission’s decision was an abuse of
its discretion. The regulation at issue explicitly confers on the
Commission a broad power to differentiate among untimely
interveners and permits the Commission to summarily reject
a prospective intervener who cannot demonstrate “good
cause” for its untimely motion. Because we find that the
Commission reasonably determined that petitioners lacked
                   CALIFORNIA TROUT v. FERC                  9165
good cause for their untimely attempt to intervene, we deny
the petition for review.

                                I

                                A

   Bufo microscaphus californicus, the arroyo southwestern
toad, is a small (two to three inch) amphibian with light
greenish gray or tan warty skin and dark spots. See Endan-
gered and Threatened Wildlife and Plants; Determination of
Endangered Status for the Arroyo Southwestern Toad, 59 Fed.
Reg. 64,859 (Dec. 16, 1994) (codified at 50 C.F.R. pt. 17).
The toad can usually be identified by its movement, which
consists of hopping (as opposed to walking or leaping), and
its high-pitched trill that adult males emit during courtship. Id.
It is not an especially peripatetic species—adult toads gener-
ally range no farther than a mile or so from the streams where
they breed, and none are known to live outside the state of
California. See Endangered and Threatened Wildlife and
Plants; Final Designation of Critical Habitat for the Arroyo
Toad, 66 Fed. Reg. 9415 (Feb. 7, 2001) (codified at 50 C.F.R.
pt. 17).

   The arroyo toad is quite particular about its habitat. It only
lives in rivers or large streams that have shallow, gravelly
pools, sandy terraces, and minimal vegetative cover. 59 Fed.
Reg. at 64,859. The adult toad deposits its eggs in these shal-
low pools, where the potentially destructive water current is
at a minimum, and the young toads eventually leave the pools
to forage for insects on the sandy terraces. Id. The larger toads
often burrow into the sandy terraces to create shelter and to
escape from the sun’s potentially lethal heat. Id. For this rea-
son, urbanization and the rapid construction of dams in Cali-
fornia beginning in the 1900s (which altered the natural water
flows on which the toad had come to depend) severely
degraded the arroyo toad’s habitat. Id. By the early 1990s,
nearly 76 percent of the species’ habitat had been degraded,
9166                 CALIFORNIA TROUT v. FERC
see 66 Fed. Reg. at 9414, and almost all the existing toad pop-
ulations were near extinction. 59 Fed. Reg. at 64,859.

   One place where the remaining arroyo toads continued to
dwell was Piru Creek, a stream that meanders south from
northwestern Los Angeles County through eastern Ventura
County until it drains into the Santa Clara River. The creek
runs through two large lakes: the northern Pyramid Lake and
the southern Piru Lake. The eighteen-mile stretch of creek
between these two lakes is known as “Middle Piru Creek.”
This area of the creek is surrounded mainly by national forest
land (the Angeles National Forest and the Los Padres
National Forest) and is used primarily for recreational activi-
ties, chief among which is fly-fishing.

   It is surprising that the species had managed to survive for
so long in Middle Piru Creek. In 1968, as part of the Califor-
nia Aqueduct Project,1 construction began on Pyramid Dam,
a 408-foot earth and rockfill edifice intended to prevent the
natural flow of water from Pyramid Lake into Middle Piru
Creek. The dam was completed in 1973, and in 1978 the
Commission licensed the California Department of Water
Resources (“DWR”) and the Los Angeles Department of
Water and Power to operate the dam and an associated power
plant. This license strictly regulated the minimum amount of
water that DWR could release from the dam at any one time.
As a result, the increased water flow emitted from Pyramid
Dam significantly altered the character of Middle Piru Creek.
  1
    The California Aqueduct is one component of the enormous “State
Water Project” designed to mitigate California’s uneven distribution of
water resources by ferrying water from the wet northern areas of the state
to the more arid south. The general history of the project is described in
the mass of California and federal case law adjudicating disputes over its
scope. See generally, e.g., In re Bay-Delta Programmatic Env. Impact
Report Coordinated Proceedings, 184 P.3d 709 (Cal. 2008); United States
v. State Water Res. Control Bd., 227 Cal. Rptr. 161 (Cal. App. 1986).
                       CALIFORNIA TROUT v. FERC                          9167
   Article 52 of the original license created the minimum flow
requirements for the release of water from Pyramid Dam:
DWR was instructed to release a continuous flow of at least
5 cubic feet per second (“cfs”) in the winter and spring and
at least 10 cfs in the summer and fall. Although these guide-
lines were slightly altered in 1982 to require occasional higher
minimum releases depending on the ambient air temperature,
they remained essentially unchanged until a confluence of
events in the early 1990s revealed their detrimental effect on
the arroyo toad.

   First, in 1992 and 1993, large inflows into Pyramid Lake
required DWR to release water at approximately 25 cfs during
some months. Then, on December 16, 1994, the arroyo toad
was officially added to the federal endangered species list.2
See 59 Fed. Reg. 64,859. Due to worries that large fluctua-
tions in the minimum flow would destroy arroyo toad eggs
and tadpoles (by stranding them on land when water flows
suddenly dropped and by washing them away when water
flows dramatically increased), DWR changed its operating
procedures—using a steady flow of 25 cfs from April through
August (when arroyo toads were breeding) and then slowly
reducing the flow during the winter months (when the tad-
poles had dispersed). Unfortunately, these operating proce-
dures, which had the effect of creating unnaturally large flows
   2
     The Endangered Species Act of 1973 (codified at 16 U.S.C. § 1531 et
seq.), called by some “the most comprehensive legislation for the preser-
vation of endangered species ever enacted,” Tenn. Valley Auth. v. Hill, 437
U.S. 153, 180 (1978), instructs the Secretary of the Interior to list any fish,
wildlife, or plant species determined to be endangered or threatened by
natural or manmade factors. 16 U.S.C. § 1533(a). Once a species is listed,
the Act makes it unlawful to “take” (“harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, or collect,” id. § 1532(19)) the species without
a permit. Id. § 1538(a)(1)(B). A person may effect a taking of (by “harm-
[ing]”) a protected species by causing “significant habitat modification or
degradation where it actually kills or injures wildlife by significantly
impairing essential behavioral patterns, including breeding, feeding, or
sheltering.” 50 C.F.R. § 17.3. See also generally Babbitt v. Sweet Home
Chapter of Cmtys. for a Great Or., 515 U.S. 687 (1995).
9168              CALIFORNIA TROUT v. FERC
during the summer months and unnaturally low flows during
the winter months, did not appear to actually benefit the toad.

   Indeed, evidence gathered during the new high flow regime
indicated that the increased flows might actually be damaging
to the arroyo toad. In 2003, the U.S. Fish and Wildlife Service
informed DWR that these unnatural flows were probably
causing the incidental take of the arroyo toad and deteriorat-
ing its habitat. Specifically, the large release of water in the
summer months created abundant vegetative growth on the
creek’s banks and encouraged increased water velocities
downstream. This allowed noxious arroyo toad predators,
such as bullfrogs, crawfish, and large-mouth bass, to multiply
throughout the creek. It also prevented the toads from repro-
ducing effectively—the large water flow eliminated the grav-
elly pools in which the toads would normally lay their eggs,
and had the more pernicious effect of washing downstream
any unprotected eggs and tadpoles. The reduced flow of water
in the winter months prevented the natural flooding that
would scour vegetation and replenish the finer sediments that
the arroyo toad preferred.

   The large summer flows did benefit at least one species in
Middle Piru Creek: rainbow trout. Because rainbow trout pre-
fer cold water (and may die if water temperatures are too
high) they benefit from a deeper (and hence cooler) habitat.
Since 1999, DWR maintained a trout fishery in the upper part
of Middle Piru Creek, known as “Frenchman’s Flat,” and
stocked it annually with around 3000 pounds of rainbow trout.
Also, a number rainbow trout inhabited the area immediately
downstream from Pyramid Dam above Frenchman’s Flat—a
designated “catch-and-release” area popular with local
anglers. Because a weir separated Frenchman’s Flat from the
catch-and-release area, those trout in the catch-and-release
area were a naturally-reproducing population not related to
the stocked fish.

   To remedy the problems the new flow regime was creating
for the arroyo toad, the Fish and Wildlife Service recom-
                   CALIFORNIA TROUT v. FERC                  9169
mended that DWR return Middle Piru Creek to a “natural
flow regime,” in which water would be released from Pyra-
mid Dam in accordance with the rate of flow from Upper Piru
Creek into Pyramid Lake. DWR accordingly filed an applica-
tion with the Commission on March 17, 2005, to amend its
license and eliminate all minimum flow requirements so as to
accurately simulate natural flows. It attached an Environmen-
tal Impact Report (“EIR”) analyzing the effects of the natural
flow regime on the wildlife of Middle Piru Creek. The EIR
concluded that a natural flow regime would expand the arroyo
toad’s habitat and diminish the populations of arroyo toad
predators. The report also concluded that populations of
naturally-breeding trout (those inhabiting the catch-and-
release area above Frenchman’s Flat) would be adversely
affected by the decreased flows. Because, however, DWR’s
analysis indicated that the naturally-reproducing trout were
genetically identical to those stocked at Frenchman’s Flat
(and thus were descendants of hatchery-raised fish rather than
a wild population), the EIR determined that this adverse
impact would not be an environmentally significant one.

                                B

  On June 8, 2005, the Commission issued public notice of
DWR’s application for a license amendment. This public
notice clearly established July 8, 2005 as the final date for fil-
ing comments or making motions (including motions to inter-
vene) in the proceedings.

   Neither CalTrout (an organization designed to preserve
California’s wild trout populations) nor FOR (an organization
designed to preserve California’s rivers) filed a motion to
intervene by the deadline. CalTrout did submit numerous
comments on the proposed license amendment: on March 26,
2005, it submitted a comment about compliance with the
Clean Water Act; on April 15, 2005, it submitted a comment
pointing out that the Fish and Wildlife Service had removed
a portion of Piru Creek from the final critical habitat designa-
9170                  CALIFORNIA TROUT v. FERC
tion for the arroyo toad; and on July 8, 2005, it submitted a
comment advising DWR that it needed to consult formally
with certain federal agencies in order to comply with the
Endangered Species Act. FOR failed to file any comments on
the draft EIR.

   The organizations’ failures to intervene were not necessar-
ily mistakes—at the time, the statutory milieu offered a sepa-
rate avenue by which CalTrout and FOR could challenge the
Commission’s proceedings. CalTrout believed that the
naturally-reproducing trout above Frenchman’s Flat might be
related to steelhead,3 an endangered trout species. See Endan-
gered and Threatened Species: Final Listing Determinations
for 10 Distinct Population Segments of West Coast Steelhead,
71 Fed. Reg. 834 (Jan. 5, 2006) (codified at 50 C.F.R. pts. 223
& 224). CalTrout thought that this genetic relationship indi-
cated that Middle Piru Creek could provide a genetic bank
that the endangered steelhead could potentially use to propa-
gate. Thus, CalTrout had expected to be able to challenge any
Commission action under the Endangered Species Act
because of its purported impact on steelhead. In January 2006,
however, the National Marine Fisheries Service published its
final rule on the designation of steelhead critical habitat under
the Endangered Species Act. See Endangered and Threatened
Species; Designation of Critical Habitat for Seven Evolutio-
narily Significant Units of Pacific Salmon and Steelhead in
California, 70 Fed. Reg. 52,488, 52,581 (Sept. 2, 2005) (codi-
fied at 50 C.F.R. pt. 226). This final rule, unlike the proposed
draft rule, did not list Middle Piru Creek as a critical habitat
for steelhead. Such a designation would have required the
Commission to consult with the National Marine Fisheries
  3
    Oncorhynchus mykiss (steelhead) are essentially rainbow trout, with
one important difference—they are anadromous, meaning that they are
born in freshwater, migrate to saltwater to spend their adult lives, and then
return to their native freshwater stream to spawn. The genetic differences
between the two species are not entirely clear—rainbow trout can give
birth to steelhead, and vice versa.
                       CALIFORNIA TROUT v. FERC                          9171
Service about protections for steelhead before implementing
the proposed action4 —and CalTrout and FOR would have
had an opportunity to challenge aspects of this consultation.
Because no actual steelhead inhabited Middle Piru Creek, the
Service’s final rule placed significant impediments on this
avenue for judicial review.5
  4
     Section 7(a)(2) of the Endangered Species Act “imposes a procedural
consultation duty whenever a federal action may affect an ESA-listed spe-
cies.” Nat’l Wildlife Fed’n v. Nat’l Marine Fisheries Serv., 524 F.3d 917,
924 (9th Cir. 2008). That section provides that “[e]ach Federal agency
shall, in consultation with and with the assistance of the Secretary [of
Commerce or the Interior], insure that any action authorized, funded, or
carried out by such agency . . . is not likely to jeopardize the continued
existence of any endangered species or threatened species.” 16 U.S.C.
§ 1536(a)(2). In cases like this where the Commission would have been
required to consult with the National Marine Fisheries Service, the Endan-
gered Species Act would have required the Fisheries Service to issue a
“written biological opinion.” See Nat’l Ass’n of Home Builders v. Defend-
ers of Wildlife, 127 S. Ct. 2518, 2526 (2007) (citing 16 U.S.C.
§ 1536(b)(3)(A)). A biological opinion must “set[ ] forth the [issuing
agency’s] opinion, and a summary of the information on which the opin-
ion is based, detailing how the agency action affects the species or its criti-
cal habitat.” 16 U.S.C. § 1536(b)(3)(A). More importantly, the issuance of
such an opinion “is considered a final agency action, and therefore subject
to judicial review.” Nat’l Wildlife Fed’n, 524 F.3d at 925 (citing Bennett
v. Spear, 520 U.S. 154, 178 (1997)).
   5
     Under regulations implementing Section 7’s consultation and biologi-
cal opinion requirement, the Commission must engage in “formal consul-
tation” (consultation resulting in the production of a biological opinion)
only in certain circumstances. See 50 C.F.R. § 402.14. If the Commission
reviews its actions and determines they will not “affect listed species or
critical habitat,” no formal consultation is required. Id. (emphasis added).
Likewise, the Commission “need not initiate formal consultation if . . . as
a result of informal consultation with the Service under [50 C.F.R.]
§ 402.13, the [the Commission] determines that the proposed action is not
likely to affect any listed species or critical habitat.” 50 C.F.R. § 402.14
(emphasis added). Because Middle Piru Creek was not listed as a critical
habitat for steelhead, it is unlikely that the Commission would have been
required to consult formally with the Fisheries Service or another agency,
and thus no biological opinion would be issued that the petitioners could
challenge. Although the petitioners could still potentially challenge the
9172                  CALIFORNIA TROUT v. FERC
   Nearly twenty-one months after it issued public notice, on
March 1, 2007, the Commission issued a draft Environmental
Assessment (“EA”) on the proposed license amendment and
solicited public comments. Both CalTrout and FOR filed
comments on the draft EA. About this same time, CalTrout
and FOR also filed untimely motions to intervene in the pro-
ceedings. CalTrout moved to intervene on April 13, 2007
(twenty-one months after the July 8, 2005 deadline). FOR
filed its motion to intervene on June 11, 2007 (twenty-three
months after the deadline and two months after it filed com-
ments on the draft EA).

   The Commission considered and rejected the motions to
intervene, holding that neither party had met the regulatory
standard for filing a late intervention motion. Both parties
sought rehearing on these decisions. The Commission denied
CalTrout’s request for rehearing on July 19, 2007. CalTrout
sought a second rehearing, which was denied on September
20, 2007. The Commission denied FOR’s rehearing request
on February 21, 2008. Both parties petitioned for review in
this court, arguing that the Commission abused its discretion
in denying their late intervention motions.

   CalTrout and FOR argue that because they clearly meet the
regulatory standard for late intervention, the Commission
acted arbitrarily and capriciously in denying their motions to
intervene. Petitioners also argue that the Commission misap-
plied its own precedent in so doing.

Commission’s decision not to engage in formal consultation, see generally
Cal. Sportfishing Prot. Alliance v. FERC, 472 F.3d 593 (9th Cir. 2006)
(discussing our jurisdiction to hear citizen suits challenging an agency
decision to forgo formal consultation), there would have been significant
obstacles to such a suit, see id. at 596-99. Moreover, it is unlikely that an
action challenging the Commission’s failure to formally consult with the
Service would have been successful if Middle Piru Creek were not a criti-
cal habitat for steelhead.
                      CALIFORNIA TROUT v. FERC                        9173
                                    II

   Our review of the Commission’s decisions is by law highly
deferential. “We examine only whether [a] decision was arbi-
trary, capricious, an abuse of discretion, unsupported by sub-
stantial evidence, or not in accordance with law.”
Steamboaters v. FERC, 759 F.2d 1382, 1388 (9th Cir. 1985).6
Here, we review the Commission’s decisions not to permit
late intervention specifically for abuse of discretion, see
Covelo Indian Cmty. v. FERC, 895 F.2d 581, 587 (9th Cir.
1990), and we may only overturn the decision if it was not
“based on a consideration of the relevant factors” or if it
evinces “a clear error of judgment.” Citizens to Preserve
Overton Park, Inc. v. Volpe, 401 U.S. 402, 416 (1971) (over-
ruled on other grounds by Califano v. Sanders, 430 U.S. 99,
105 (1977)). In accordance with Chevron, we must also give
“substantial deference” to the Commission’s interpretation of
its own regulations. Thomas Jefferson Univ. v. Shalala, 512
U.S. 504, 512 (1994). “In other words, we must defer to the
[Commission’s] interpretation unless an alternative reading is
compelled by the regulation’s plain language or by other indi-
cations of the [Commission’s] intent at the time of the regula-
tion’s promulgation.” Id. (internal quotation marks omitted);
see generally Chevron U.S.A., Inc. v. Natural Res. Def. Coun-
cil, Inc., 467 U.S. 837, 865-66 (1984) . Likewise, we must
give deference to the Commission’s interpretation of its own
orders. Cal. Dep’t of Water Res. v. FERC, 489 F.3d 1029,
1036 (9th Cir. 2007).
  6
    As the D.C. Circuit has noted, “[t]he judicial review provision govern-
ing petitions for review of FERC orders was drafted long before the pas-
sage of the APA; concerning the scope of review, it explicitly states only
that the finding of ‘the Commission as to the facts if supported by substan-
tial evidence shall be conclusive.’ ” Bangor Hydro-Elec. Co. v. FERC, 78
F.3d 659, 663 (D.C. Cir. 1996) (quoting 16 U.S.C. 825l(b)) (emphasis
removed). Because we, like the D.C. Circuit, have recognized that “the
Court reads the statute implicitly as providing review on arbitrary and
capricious grounds,” see id., we review the Commission’s decisions under
both standards. Steamboaters, 759 F.2d at 1388.
9174              CALIFORNIA TROUT v. FERC
                               A

   The Commission operates under the Federal Power Act
(“the Act”), a “complete scheme of national regulation”
intended to “promote the comprehensive development of the
water resources of the Nation.” First Iowa Hydro-Elec. Coop.
v. FPC, 328 U.S. 152, 180 (1946). The Act authorizes the
Commission to “issue licenses . . . for the purpose of con-
structing, operating, and maintaining dams [or other hydro-
electric projects] . . . for the development and improvement
of navigation and for the development, transmission, and utili-
zation of power across, along, from, or in any of the streams
or other bodies of water over which Congress has jurisdic-
tion.” 16 U.S.C. § 797. Although these licenses are normally
binding for several decades, see 16 U.S.C. § 799 (setting fifty
years as the maximum life of a license), they can be amended,
as here, upon application by the licensee and public notice. 16
U.S.C. § 799. In amending a license, the Commission must
comply with the requirements of the National Environmental
Policy Act (“NEPA”), which directs all federal agencies, “to
the fullest extent possible,” to prepare “a detailed statement
on . . . the environmental impact” of “major Federal actions
significantly affecting the quality of the human environment.”
42 U.S.C. § 4332(2)(C)(i).

   The Federal Power Act specifically “prescribe[s] the proce-
dures and conditions under which, and the courts in which,
judicial review of [the Commission’s] orders may be had.”
City of Tacoma v. Taxpayers of Tacoma, 357 U.S. 320, 336
(1958). Section 313 of the Act provides that only “parties” to
Commission proceedings may seek administrative or judicial
review of the Commission’s final orders. See 16 U.S.C.
§ 825l(a) (“Any person . . . aggrieved by an order issued by
the Commission in a proceeding under this chapter to which
such person . . . is a party may apply for a rehearing . . . .”);
id. § 825l(b) (“Any party to a proceeding under this chapter
aggrieved by an order issued by the Commission in such pro-
ceeding may obtain a review of such order in [a specified]
                       CALIFORNIA TROUT v. FERC                          9175
United States Court of Appeals . . . .”). Because section 313
enumerates “the specific, complete and exclusive mode for
judicial review of the Commission’s orders,” City of Tacoma,
357 U.S. at 336, a non-party to the Commission’s proceedings
may not challenge the Commission’s final determination in
any court.7

   Section 308 of the Act gives the Commission the power to
promulgate regulations governing the process through which
interested persons become “parties” within the meaning of the
Act. Section 308(a) provides:

      In any proceeding before it, the Commission, in
      accordance with such rules and regulations as it
      may prescribe, may admit as a party any interested
      State, State commission, municipality, or any repre-
      sentative of interested consumers or security holders,
      or any competitor of a party to such proceeding, or
      any other person whose participation in the proceed-
      ing may be in the public interest.

16 U.S.C. § 825g(a) (emphasis added).

   [1] Pursuant to this statutory authority, the Commission has
promulgated Rule 214, which governs what persons may
intervene and thereby become parties in Commission pro-
ceedings. See 18 C.F.R. § 385.214. Under the rule, a person
who fails to intervene may not become a party and later chal-
  7
    There is an equitable exemption to this rule for petitioners challenging
the Commission’s denial of party status, because “[i]t would be grossly
unfair to deny judicial review to a petitioner objecting to an agency’s
refusal to grant party status on the basis that the petitioner lacks party sta-
tus.” Covelo Indian Cmty., 895 F.2d at 586 (quoting N. Colo. Water Con-
servancy Dist. v. FERC, 730 F.2d 1509, 1515 (D.C. Cir. 1984)) (internal
quotation marks omitted). In such cases, the petitioner is “considered a
party for the limited purpose of reviewing the agency’s basis for denying
party status.” Id. (quoting N. Colo. Water Conservancy Dist., 730 F.2d at
1515) (internal quotation marks omitted).
9176                CALIFORNIA TROUT v. FERC
lenge the ultimate agency determination. See Covelo Indian
Cmty., 895 F.2d at 585-86 (“When FERC issued the relicense,
it also denied the [petitioner’s] motion to intervene, thereby
denying the [petitioner] party status.”). Rule 214 does not cat-
egorically bar intervention for persons filing untimely
motions. Instead, the rule provides that the Commission may
allow interested persons to intervene after the deadline for
such interventions has passed, and enumerates specific cir-
cumstances in which the time limitations may be waived.

   [2] Under Rule 214, a timely movant must simply “state, to
the extent known, the position taken by the movant and the
basis in fact and law for that position,” 18 C.F.R.
§ 385.214(b)(1), and demonstrate with enough factual detail
that the movant either has a statutory or regulatory right to
participate, “represents an interest which may be directly
affected by the outcome of the proceeding,” or that its partici-
pation would be in the public interest. Id. § 385.214(b)(2). An
untimely movant must demonstrate more: he must “show
good cause why the time limitation should be waived.” Id.
§ 385.214(b)(3). Rule 214 also enumerates specific factors
that Commission “may” consider in acting upon such a
motion. Specifically, the Commission “may consider whether
(i) [t]he movant had good cause for failing to file the motion
within the time prescribed; (ii) [a]ny disruption of the pro-
ceeding might result from permitting intervention; (iii) [t]he
movant’s interest is not adequately represented by other par-
ties in the proceeding; (iv) [a]ny prejudice to, or additional
burden upon, the existing parties might result from permitting
the intervention;” and (v) the motion conforms to the regula-
tion’s basic procedural requirements. Id. § 385.214(d)(1). In
other words, an untimely movant must, at a minimum, dem-
onstrate good cause and, in addition, should address the fur-
ther factors the Commission may consider in its discretion.8
  8
    We note that Rule 214 does not appear to require the Commission to
reject an untimely movant who has failed to “show good cause why the
                      CALIFORNIA TROUT v. FERC                        9177
   [3] Rule 214’s language allots broad discretion to the Com-
mission to grant or deny an untimely motion for intervention.
The rule neither conclusively defines “good cause” nor sug-
gests that a showing of all the enumerated factors will satisfy
a petitioner’s burden. Indeed, the use of the permissive “may”
rather than the obligatory “shall” suggests that the Commis-
sion may not only consider other, non-enumerated factors in
adjudicating a motion for untimely intervention, but can affir-
matively abstain from including even one or more of the enu-
merated factors in its decisional calculus. See id.
§ 385.214(d)(1). See also Power Co. of Am., L.P. v. FERC,
245 F.3d 839, 843 (D.C. Cir. 2001) (“Failure to establish
good cause is . . . a sufficient condition to deny intervention,
so the Commission was not obligated to consider any other
factor.”); City of Orrville v. FERC, 147 F.3d 979, 991 (D.C.
Cir. 1998) (“The text of [Rule 214] does not compel consider-
ation of each of the factors. . . .”). Additionally, because the
regulation does not indicate what weight the Commission is
required to place on each enumerated factor, even a failure to
prove one of the factors could be sufficient to support the
Commission’s        decision      to    deny      intervention—
notwithstanding a successful showing of good cause.

                                    B

  Petitioners make two objections to the Commission’s appli-
cation of Rule 214. First, petitioners claim that the Commis-

time limitation should be waived,” 18 C.F.R. § 385.214(b)(3). The
requirement that an untimely movant make a showing of good cause is
found in paragraph (b) of Rule 214, and thus is a factor that the Commis-
sion “may” consider in acting on the motion to intervene. See id.
§ 385.214(d)(1)(v) (“[T]he decisional authority may consider whether . . .
[t]he motion conforms to the requirements of paragraph (b) of this sec-
tion.”). See also Alaska Power & Tel. Co., 98 F.E.R.C. ¶ 61,092, 61,278
(2002) (“In short, there is no right to late intervention in Commission pro-
ceedings under Rule 214. Rather, the rule affords the Commission the dis-
cretion to grant late intervention based on a showing of good cause, as
well as consideration of other relevant factors.”).
9178                  CALIFORNIA TROUT v. FERC
sion arbitrarily and capriciously ignored facts establishing
good cause for their untimely intervention. Second, petition-
ers assert that the Commission acted arbitrarily and capri-
ciously in assessing Rule 214’s other enumerated factors—
which petitioners claim weigh strongly in favor of allowing
late intervention. Because, as discussed below, neither of
these arguments is persuasive, we deny petitioners’ request to
overturn the Commission’s determinations on such a basis.

                                      1

   Petitioners first argue that the Commission failed to cor-
rectly apply the “good cause” standard when rejecting their
untimely intervention motions. Petitioners claim that the
Commission’s decision to issue an EA rather than a full-
fledged Environmental Impact Statement (“EIS”) gave them
good cause to intervene. They contend that NEPA mandates
intervention in such cases where an agency issues an EA.
Additionally, petitioners assert that new information revealed
after the July 8, 2005 intervention deadline gave them good
cause to intervene.9
  9
    Petitioners also argue that certain provisions of the Endangered Species
Act require a finding of good cause. Because petitioners failed to present
this argument to the Commission, however, and have not convinced us
that there was a reasonable ground for their failure to do so, we cannot
rule on it for the first time on appeal. See 16 U.S.C. § 825l(b) (“No objec-
tion to the order of the Commission shall be considered by the court unless
such objection shall have been urged before the Commission in the appli-
cation for rehearing unless there is reasonable ground for failure so to
do.”); High Country Res. v. FERC, 255 F.3d 741, 745-46 (9th Cir. 2001)
(requiring a petitioner to specifically and unambiguously raise an objec-
tion in a request for rehearing before bringing it to the appellate court).
Although petitioners raised such objections in their initial requests for late
intervention, this is not sufficient—petitioners failed to make the same
objections in their applications for rehearing before the Commission. See
16 U.S.C. § 825l(b).
                  CALIFORNIA TROUT v. FERC                 9179
                   The Issuance of the EA

   [4] Under NEPA, if an agency determines that a project
will “significant[ly] affect[ ]” the environment, the agency
must prepare an EIS, “a detailed statement on . . . the environ-
mental impact” of the proposed project. 42 U.S.C.
§ 4332(2)(C). “As a preliminary step, an agency may prepare
an EA in order to determine whether the environmental
impact of a proposed action is significant enough to warrant
preparation of an EIS.” Blue Mountains Biodiversity Project
v. Blackwood, 161 F.3d 1208, 1212 (9th Cir. 1998). See 40
C.F.R. § 1508.9 (describing an EA as a “concise public docu-
ment . . . that serves to [b]riefly provide sufficient evidence
and analysis for determining whether to prepare an environ-
mental impact statement or a finding of no significant
impact.”). An agency must go further, and prepare an EIS, “if
substantial questions are raised as to whether a project may
cause significant degradation of some human environmental
factor.” LaFlamme v. FERC, 852 F.2d 389, 397 (9th Cir.
1988) (internal alterations and quotation marks omitted). See
40 C.F.R. § 1502.1 (describing the basic contents of an EIS).
An EA “need not conform to all the requirements of an EIS,
[but] it must be sufficient to establish the reasonableness of
the decision not to prepare an EIS.” Ctr. for Biological Diver-
sity v. Nat. Hwy. Traffic Safety Admin., 538 F.3d 1172, 1215
(9th Cir. 2008) (quotations and alteration omitted).

   Although NEPA does not require federal agencies to “as-
sess . . . consider . . . [and] respond” to public comments on
an EA to the same degree as it does for an EIS, see 40 C.F.R.
§ 1503.4, an agency must permit some public participation
when it issues an EA. In particular, the agency must “involve
environmental agencies, applicants, and the public, to the
extent practicable,” id. § 1501.4(b), and “[m]ake diligent
efforts to involve the public in preparing and implementing
their NEPA procedures,” id. § 1506.6(a).

   [5] In implementing NEPA’s requirements for public par-
ticipation, the Commission has promulgated a rule automati-
9180              CALIFORNIA TROUT v. FERC
cally permitting late intervention when it issues a draft EIS.
See 18 C.F.R. § 380.10(a)(1). This rule provides that “[i]n
addition to submitting comments on the NEPA process and
NEPA related documents, any person may file a motion to
intervene in a Commission proceeding dealing with environ-
mental issues under the terms of [Rule 214].” Id.
§ 380.10(a)(1)(i). So long as such a motion “is filed within the
comment period for the draft environmental impact state-
ment” it will be deemed timely under Rule 214. Id.
§ 380.10(a)(1)(i). The Commission has no similar rule for
motions filed during the comment period for a draft EA. See
Cameron LNG, LLC, 118 F.E.R.C. ¶ 61,019 (2007).

   [6] Given this regulatory background, it is clear that the
Commission does not consider the mere issuance of a draft
EA to be determinative of good cause under Rule 214. If it
did, the Commission would have promulgated a rule automat-
ically permitting late intervention when it issued a draft EA,
as it has done for those occasions where it issues a draft EIS.
In the absence of such a rule, we cannot find the Commis-
sion’s determinations that petitioners lacked good cause arbi-
trary and capricious simply because the Commission issued a
draft EA.

   Petitioners contend that because in this case the Commis-
sion’s decision to issue an EA and not an EIS violated NEPA
(and was thus “unexpected”), the draft EA gave them good
cause to intervene. But petitioners have put the cart before the
horse—they essentially argue that because they are about to
be denied the benefits of intervention they should be deemed
as having good cause to intervene. If the Commission’s deci-
sion to issue an EA rather than an EIS violates NEPA, the
proper course is for petitioners to challenge that decision in
the proper forum. See 16 U.S.C. § 825l(b). Of course, because
of their mistake in failing to intervene, petitioners now lack
standing to pursue such a suit. See id. § 825l(b) (“Any party
to a proceeding under this chapter aggrieved by an order
issued by the Commission in such proceeding may obtain
                      CALIFORNIA TROUT v. FERC                         9181
[judicial] review . . . .” (emphasis added)); Covelo Indian
Cmty., 895 F.2d at 585. It turns Rule 214 on its head, how-
ever, to argue that this lack of standing gives the petitioners
good cause to intervene. If, as petitioners claim, losing one of
the benefits of intervention constitutes “good cause” under
Rule 214, then that rule is truly toothless—no untimely peti-
tioner will ever lack good cause, since by definition no peti-
tioner can obtain the benefits of intervention until he actually
intervenes.10

  Petitioners also argue that the Commission’s failure to pro-
vide an exemption for intervention in cases where it issues a
draft EA violates NEPA’s requirement that it “involve envi-
ronmental agencies, applicants, and the public, to the extent
practicable.” 40 C.F.R. § 1501.4(b); see also id. § 1506.6.
This argument overstates the pertinent NEPA regulations.

   Although we have not unequivocally defined what sort of
public participation is required to meet NEPA’s amorphous
standards, we have recognized that the level of participation
required by NEPA’s implementing regulations is not substan-
tial. We have held that “a complete failure to involve or even
inform the public about an agency’s preparation of an EA”
would violate NEPA’s regulations, see Citizens for Better
Forestry v. U.S. Dep’t of Agric., 341 F.3d 961, 970 (9th Cir.
2003), but have also concluded that “the circulation of a draft
EA is not required in every case.” Bering Strait Citizens for
Responsible Res. Dev. v. U.S. Army Corps of Eng’rs, 524 F.3d
938, 952 (9th Cir. 2008).

  [7] We have never suggested that intervention—much less
untimely intervention—is necessary to satisfy NEPA’s
  10
     The Commission has rejected variations on petitioners’ argument
numerous times. See, e.g., PJM Interconnection, LLC, 116 F.E.R.C. ¶
63,031 (2006); Transok, L.L.C., 89 F.E.R.C. ¶ 61,055 (1999) (“By failing
to intervene in a timely fashion, [petitioner] assumed the risk that the par-
ties would settle the case in a manner not to its liking.”)
9182              CALIFORNIA TROUT v. FERC
requirements. In Citizens for Better Forestry, we remarked
that 40 C.F.R. § 1501.4(b) and 40 C.F.R. § 1506.6 meant that
“the public must be given an opportunity to comment on draft
EAs.” 341 F.3d at 970 (quoting Anderson v. Evans, 314 F.3d
1006, 1016 (9th Cir. 2002)) (internal quotation marks and
alteration omitted). Similarly, in Bering Strait Citizens, we
concluded that “[a]n agency, when preparing an EA, must
provide the public with sufficient environmental information,
considered in the totality of the circumstances, to permit
members of the public to weigh in with their views and thus
inform the agency decision-making process.” 524 F.3d at 953.
But neither enabling the public to comment nor providing the
public with sufficient information to elicit informed responses
requires intervention. Non-parties to the Commission’s pro-
ceedings are not prevented from commenting on proposed
actions or receiving information about the Commission’s
decisions. Instead, non-parties are simply unable to challenge
the Commission’s final decision in court.

   [8] In this case, the Commission fully satisfied the partici-
pation standards we have sublimated from NEPA’s imple-
menting regulations. The Commission circulated a draft EA
and solicited comments, and both CalTrout and FOR filed
comments on the draft EA. In its decisions denying petition-
ers’ motions for intervention, the Commission noted that “it
[would] consider all comments from [petitioners] with full
weight,” see 120 F.E.R.C. ¶ 61,057 n.9 (CalTrout); 122
F.E.R.C. ¶ 61,150 (FOR), and petitioners have not suggested
otherwise. Petitioners were given a full opportunity to review
and comment on the draft EA, as NEPA requires, and they
took advantage of that opportunity. We decline to broaden
NEPA by construing it to require intervention in such cases
as well.

                       New Information

   Petitioners also assert that new information alerted them to
the importance of intervening in the action after the regulatory
                     CALIFORNIA TROUT v. FERC                       9183
deadline had passed. Specifically, petitioners cite three events
that they contend create good cause for untimely intervention:
(1) the National Marine Fisheries Service’s issuance of a final
rule in January 2006 failing to list Middle Piru Creek as a crit-
ical habitat for endangered steelhead trout, see 70 Fed. Reg.
at 52,581; (2) a November 2006 report by Fisheries Service
scientists working with the California Department of Fish and
Game providing evidence that rainbow trout in the Middle
Piru Creek are descended from steelhead trout rather than
hatchery populations;11 and (3) a February 2006 report by a
consultant to DWR (that petitioners claim they were not able
to access until April 2007) indicating that the arroyo toad
increased in population in 2005, when there were large sum-
mer flows in Middle Piru Creek.12

   As the Commission pointed out, none of these events
divulged a new issue with the license amendment. CalTrout
was plainly aware of the potential impact of the license
amendment on the wild trout in Piru Creek—in fact, it sub-
mitted several comments on that very topic to the Commis-
sion before the July 8, 2005, deadline for intervention. On
April 6, 2005 (three months before the deadline for interven-
tions) CalTrout commented that “the [license amendment]
may result in a violation of the Endangered Species Act . . .
because of its impact on the Southern California steelhead.”
On April 25, 2005 (still well within the deadline for interven-
tion), it submitted another comment noting that the Fisheries
Service “has identified through genetic testing the trout in this
reach of Piru Creek are native rainbow trout.” Finally, Cal-
   11
      D. Girman & J. C. Garza, Population structure and ancestry of O.
mykiss populations in South-Central California based on genetic analysis
of microsatellite data, Final Report of the National Marine Fisheries Ser-
vice, Southwest Fisheries Science Center, Santa Cruz, California, for the
California Department of Fish and Game Project No. P0350021 and
Pacific States Marine Fisheries, Contract No. AWIP-S (Nov. 2006).
   12
      Nancy H. Sandburg, Middle Piru Creek Arroyo Toads (Bufo cali-
fornicus) Clutch Surveys 2006, prepared for the California Department of
Water Resources (Feb. 2006).
9184              CALIFORNIA TROUT v. FERC
Trout filed a comment a few days after the deadline for inter-
vention (on July 14, 2005) asserting that “the amendment
request may have an adverse impact on the federally listed
steelhead” and that failure to consult with the Fish and Wild-
life Service about the steelhead might open the Commission
to “significant citizen suit liabilities.”

   CalTrout also maintained in these comments that the cur-
rent flow regime did not significantly damage the arroyo toad.
CalTrout’s April 6th comment claimed that “past project
operations and bypass instream flow releases to Piru Creek
below Pyramid Dam have generally benefitted the resource,
including the listed Arroyo Toad.” This comment argued that
“alternative flow regimes warrant further consideration.”

   Although FOR did not file similar comments, it was also
aware of the issues it now presents. First, in November 2004,
FOR was served with a copy of DWR’s EIR, prepared in
expectation of its license amendment. The EIR described in
detail the reasons DWR believed the current flow regime was
harming the arroyo toad, and the reasons DWR believed a
natural flow regime would not harm the endangered steel-
head. Later, in March 2005, FOR was served with a copy of
DWR’s request for a license amendment. This document
described the proposed flow regime change and specifically
noted that the Fisheries Service had proposed making portions
of Middle Piru Creek a critical habitat for steelhead. Thus,
beginning in March 2005, several months before the deadline
for intervention, FOR had notice that at least one government
agency considered Middle Piru Creek a potentially important
habitat for steelhead trout; that DWR was applying to change
its flow regime in a manner that might result in harm to what-
ever fish species inhabited the creek; and that DWR was
doing so because it believed the new flow regime would bene-
fit the arroyo toad. Although FOR did not have strong scien-
tific support for its arguments that a natural flow regime
would harm steelhead and not help the arroyo toad, it knew
                     CALIFORNIA TROUT v. FERC                       9185
that these would be the environmental issues surrounding
DWR’s license amendment.

   [9] In sum, although the 2006 reports now cited by the peti-
tioners provided better support for petitioners’ contentions,
they did not fundamentally change the issues (or even the
arguments) involved. Thus, it was not an abuse of discretion
for the Commission to decide that this “new information” did
not give petitioners good cause to intervene late. Indeed, it
was consistent with the Commission’s extant precedent. See,
e.g., S. Cal. Edison Co., 100 F.E.R.C. ¶ 61,327 (2002)
(“Choosing to focus on other matters rather than to timely
respond to a filing before this Commission falls far short of
the demonstration of good cause that would support a late
intervention request.”); Niagara Mohawk Power Corp., 100
F.E.R.C. ¶ 61,247 (2002) (“[Because, b]y their own admis-
sion, [petitioners] had some indication that [licensee’s] filings
in these proceedings may affect their interests,” the fact that
petitioners claimed that “there appeared to be no disputes rel-
evant to their interests” was not enough to establish good
cause for untimely intervention).

   In support of their argument that new information can con-
stitute good cause under Rule 214, petitioners present only
dicta in two cases involving the Nuclear Regulatory Commis-
sion (“NRC”). Neither case is analogous. In Sierra Club v.
NRC, 862 F.2d 222 (9th Cir. 1988), we addressed whether a
late-filed “contention” (issue) with the NRC was “rea-
sonabl[y] specific[ ]” enough (under NRC regulations) to be
considered. Id. at 226. We noted in dicta, in a footnote, that
under the NRC’s regulation governing late-filed contentions,13
  13
     Although the NRC’s rule governing the untimely admission of conten-
tions is similar to the Commission’s Rule 214, there are several important
differences. For example, the NRC’s rule, unlike Rule 214, instructs the
NRC to consider “[t]he availability of other means whereby the petition-
er’s interest will be protected” in addition to “[t]he extent to which the
petitioner’s interest will be represented by existing parties.” See Sierra
Club, 862 F.2d at 227 (quoting 10 C.F.R. § 2.714(a)(1) (1988)).
9186              CALIFORNIA TROUT v. FERC
new information issued after the deadline for filing conten-
tions could constitute “good cause” for late filing. Id. at 227
n.6. The information in Sierra Club, however, revealed a
safety issue theretofore not considered. See id. at 224. Like-
wise, in Union of Concerned Scientists v. NRC, 920 F.2d 50
(D.C. Cir. 1990), the D.C. Circuit noted in dicta that the NRC
has ruled that “good cause” under its late-filing rule is “by
definition” met “where contentions are filed late only because
the information on which they were based was not available
until after the filing deadline.” Id. at 52-53.

   Even if we thought that dicta in two NRC cases should
inform our judgment about the Federal Energy Regulatory
Commission’s proceedings, neither case gives us any reason
to question the Commission’s interpretation of its regulations
governing late intervention. In both cases, the “new informa-
tion” on which petitioners relied was actually new, and
revealed an issue not previously considered by either the NRC
or the petitioners. In this case, the “new information” does not
reveal any new issues: it is simply stronger scientific support
for arguments already made to the Commission.

   [10] Moreover, even if we thought that the 2006 reports
supplied good cause for late intervention, the petitioners were
still untimely. These reports, and the new Fisheries Service
rule, were issued in 2006, and yet petitioners failed to move
to intervene until mid-2007—almost a year after the first of
the information became available. Given these circumstances,
we cannot find arbitrary and capricious the Commission’s
determinations that new information did not excuse petition-
ers’ failure to intervene in a timely fashion.

                               2

   Petitioners also claim that the Commission’s determina-
tions that CalTrout and FOR’s late intervention would preju-
dice the other parties to the proceedings were arbitrary and
capricious. They note that (1) no other party opposed their
                  CALIFORNIA TROUT v. FERC                 9187
late intervention motions, (2) DWR was the only other party
to the proceeding, (3) the Commission could not legally issue
a license amendment until California issued a water quality
certification for the project pursuant to the Clean Water Act—
a process that is ongoing, and (4) DWR is currently operating
Pyramid Dam under an “interim” flow regime substantially
similar to that proposed in the license amendment, and thus
cannot be prejudiced by prolonged proceedings. Petitioners
assert that the Commission’s decisions, by failing to account
for these facts and by failing to explicitly discuss the factors
constituting prejudice under Rule 214, are arbitrary and capri-
cious.

   [11] Rule 214 sets out five factors that the Commission
“may” consider when acting on an untimely motion to inter-
vene. The first factor gives the Commission the discretion to
consider whether “the movant had good cause for failing to
file the motion within the time prescribed.” 18 C.F.R.
§ 385.214(d)(1)(I). The next three factors constitute the
inquiry into “prejudice.” The second factor asks whether
“[a]ny disruption of the proceeding might result from permit-
ting intervention.” Id. § 385.214(d)(1)(ii). The third factor
looks to whether “[t]he movant’s interest is not adequately
represented by other parties in the proceeding.” Id.
§ 385.214(d)(1)(iii). The fourth factor inquires whether “[a]ny
prejudice to, or additional burdens upon, the existing parties
might result from permitting the intervention.” Id.
§ 385.214(d)(1)(iv). The fifth factor allows the Commission
to determine whether the “motion conforms to the require-
ments of paragraph (b),” id. § 385.214(d)(1)(v), including the
requirement that the movant “show good cause why the time
limitation should be waived,” id. § 385.214(b)(3).

   The Commission’s orders denying rehearing on CalTrout
and FOR’s motions for untimely intervention do not compre-
hensively address any of the three factors constituting “preju-
dice.” In its order denying rehearing of FOR’s motion, the
Commission mentions “prejudice” but does not explain either
9188              CALIFORNIA TROUT v. FERC
the basis for finding prejudice or the weight such a finding
played in its determination. The Commission notes that its
“rules are designed to ensure an orderly administrative pro-
cess and the certainty that there will be an end to interventions
which prolong the proceeding.” 122 F.E.R.C. ¶ 61,150 (inter-
nal quotation marks omitted). After analyzing whether the
new information cited by FOR could give it good cause to
intervene, the Commission then concludes that “[a]llowing
interventions, 21 months after the deadline, would delay, prej-
udice, and place additional burdens on the Commission and
the licensees.” Id. It reasons that “[w]ere the Commission to
allow new intervention every time a study was conducted or
new information was otherwise placed in the record, we
would never be able to establish a deadline for interventions,
which is necessary for us to conduct orderly proceedings.” Id.
Similarly, when rejecting CalTrout’s motion for rehearing, the
Commission declares that “[a]llowing intervention, 19 months
after the deadline, would delay, prejudice, and place addi-
tional burdens on the Commission and the licensees.” 120
F.E.R.C. ¶ 61,057. Neither decision addresses whether any
disruption of the proceeding might result, whether CalTrout’s
or FOR’s interests would be adequately represented, or how
exactly petitioners untimely intervention would “prejudice” or
“place additional burdens upon” DWR, the only party to the
proceedings. Cf. 18 C.F.R. § 385.214(d)(1).

   The Supreme Court has advised that “the scope of review
under the ‘arbitrary and capricious’ standard is narrow and a
court is not to substitute its judgment for that of the agency.”
Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut.
Auto. Ins. Co., 463 U.S. 29, 43 (1983). Although “the agency
must examine the relevant data and articulate a satisfactory
explanation for its action including ‘a rational connection
between the facts found and the choice made,’ ” id. (quoting
Burlington Truck Lines v. United States, 371 U.S. 156, 168
(1962)), and “the reviewing court should not attempt itself to
make up for [any] deficiencies [in the agency’s reasoning],”
id. (citing SEC v. Chenery Corp., 332 U.S. 194, 196 (1947)),
                  CALIFORNIA TROUT v. FERC                9189
we should “uphold a decision of less than ideal clarity if the
agency’s path may reasonably be discerned.” Id. (quoting
Bowman Transp. Inc. v. Ark.-Best Freight Sys., 419 U.S. 281,
286 (1974)) (internal quotation marks omitted).

   The Commission’s explanations are not “a paragon of clari-
ty.” Nw. Ecosystem Alliance v. U.S. Fish & Wildlife Serv.,
475 F.3d 1136, 1146 (9th Cir. 2007). Both orders denying
rehearing mention “delay” and “prejudice” almost as throw-
away points—the Commission refers to these factors in a sin-
gle line, in the middle of a paragraph otherwise discussing
whether new information might present good cause for late
intervention. See 122 F.E.R.C. ¶ 61,150; 120 F.E.R.C. ¶
61,057. Additionally, both decisions discuss the factors in the
abstract and do not enumerate the specific reasons why Cal-
Trout or FOR’s intervention would prejudice or delay the pro-
ceedings. Indeed, the Commissions’ decisions appear to
simply employ boilerplate language from prior decisions in
this regard. Cf., e.g., S. Cal. Edison Co., 112 F.E.R.C. ¶
61,014 (2005) (noting “the absence of any undue delay, preju-
dice or burden to the parties”); Sw. Power Pool, Inc., 111
F.E.R.C. ¶ 61,118 (2005) (same).

   [12] Nevertheless, we think that due to the peculiar nature
of the regulation at issue, the Commission’s path “may rea-
sonably be discerned.” See Alaska Dep’t of Envtl. Conserva-
tion v. EPA, 540 U.S. 461, 497 (2004). Under Rule 214, the
Commission has the discretion to consider good cause, preju-
dice, and other factors before granting or denying a movant’s
request for untimely intervention. Good cause is plainly the
most important consideration because it is mentioned twice in
the Commission’s regulation. A motion for intervention “must
. . . show good cause why the time limitation shall be
waived.” 18 C.F.R. § 385.214(b)(3) (emphasis added). The
Commission may consider whether the motion “conforms to
the [procedural] requirements” of paragraph (b),” id.
§ 385.214(d)(1)(v), and whether “the movant had good cause
for failing to file the motion within the time prescribed,” id.
9190              CALIFORNIA TROUT v. FERC
§ 385.214(d)(1)(i). A finding that a movant has failed to show
good cause is a sufficient basis for denying late intervention.
If the Commission determines that the movant failed to show
good cause, it “may,” but is not required to, consider any
other factor, including prejudice.

   [13] In other words, a late petitioner must ordinarily show
“good cause” and, once that is shown, additionally prove that
the late intervention will not prejudice the Commission or
other parties. If the Commission determines that an untimely
movant lacks good cause, the Commission is not required to
consider the remaining factors. See Power Co. of Am., 245
F.3d at 843. Under the Commission’s regulation, lack of prej-
udice is not the same as “good cause.” Here, the Commission
clearly found that neither FOR nor CalTrout had presented
good cause for its untimely intervention. See 122 F.E.R.C. ¶
61,150; 120 F.E.R.C. ¶ 61,057. The Commission discussed at
length FOR’s and CalTrout’s failure to provide “any convinc-
ing reasons why it could not have intervened earlier in the
proceeding,” concluded that the allegedly new information
could not provide good cause for FOR to intervene, and held
that late intervention “was [not] warranted by the long-
standing principles [of NEPA].” 122 F.E.R.C. ¶ 61,150. See
also 120 F.E.R.C. ¶ 61,057. We thus do not need to “guess
at the theory underlying the agency’s action,” Chenery Corp.,
332 U.S. at 196-97, or “infer an agency’s reasoning from
mere silence,” Pac. Coast Fed’n of Fishermen’s Ass’ns v.
U.S. Bureau of Reclamation, 426 F.3d 1082, 1091 (9th Cir.
2005) (internal quotation marks omitted). The Commission
made clear that petitioners lacked any viable reason for their
failure to intervene earlier in the proceedings, and was justi-
fied in denying their motions for late intervention solely on
that basis, even if, as petitioners claim, no prejudice would
result from their untimely intervention. We cannot conclude
that by mentioning factors not necessary to its holding, the
Commission acted arbitrarily and capriciously or otherwise
abused its discretion.
                  CALIFORNIA TROUT v. FERC                 9191
                               C

   Petitioners also object that the Commission’s actions are
inconsistent with its precedent. Petitioners claim that the
Commission inexplicably departed from several prior deci-
sions in which similarly positioned movants were permitted to
intervene after the regulatory deadline, and thus that the Com-
mission’s decision was arbitrary and capricious. See Atchin-
son, Topeka, & Santa Fe Ry. v. Wichita Bd. of Trade, 412
U.S. 800, 808 (1973) (plurality opinion).

   [14] We generally expect agencies to deal consistently with
the parties or persons coming before them. “Not only must an
agency’s decreed result be within the scope of its lawful
authority, but the process by which it reaches that result must
be logical and rational.” Allentown Mack Sales & Serv., Inc.
v. NLRB, 522 U.S. 359, 374 (1998). If an agency fails to
adhere to “the rules developed in its precedent, those subject
to the agency’s authority cannot use its precedent as a guide
for their conduct; nor will that precedent check arbitrary
agency action.” Shaw’s Supermarkets, Inc. v. NLRB, 884 F.2d
34, 41 (1st Cir. 1989) (Breyer, J.). Accordingly, “[a] settled
course of behavior embodies the agency’s informed judgment
that, by pursuing that course, it will carry out the policies
committed to it by Congress.” Atchinson, Topeka, & Santa Fe
Ry., 412 U.S. at 807.

   Consistency is not the only value at issue. Within certain
bounds, “[f]ederal agencies have the power to adjust policies
and rulings in light of experience.” Cal. Trucking Ass’n v.
Interstate Commerce Comm’n, 900 F.2d 208, 212 (9th Cir.
1990) (quoting Mont. Power Co. v. Envtl. Prot. Agency, 608
F.2d 334, 347 (9th Cir. 1979) (quotation marks and alteration
omitted). An agency’s learned expertise with certain types of
decisions gives it the ability to make the sort of informed pol-
icy choices that we cannot.

   [15] The intersection of these principles gives rise to our
standard of review for agency decisions interpreting its prior
9192                 CALIFORNIA TROUT v. FERC
holdings. Thus, “while an agency may announce new princi-
ples in an adjudicatory proceeding, it ‘may not depart, sub
silentio, from its usual rules of decision to reach a different,
unexplained result in a single case.’ ” Id. (quoting NLRB v.
Silver Bay Local Union No. 962, 498 F.2d 26, 29 (9th Cir.
1974). See NLRB v. Bell Aerospace Co., 416 U.S. 267, 294
(1974). In other words, “[t]hough the agency’s discretion is
unfettered at the outset, if it announces and follows—by rule
or by settled course of adjudication—a general policy by
which its exercise of discretion will be governed, an irrational
departure from that policy (as opposed to an avowed alter-
ation of it) could constitute action that must be overturned as
‘arbitrary, capricious, [or] an abuse of discretion’ within the
meaning of the Administrative Procedure Act.” INS v. Yueh-
Shaio Yang, 519 U.S. 26, 32 (1996).

   Our task accordingly is to assess whether the cases petition-
ers cite indicate that the Commission departed irrationally
from its prior decisions. If we so conclude, then we must ana-
lyze the Commission’s reasons from departing from its past
precedent to determine whether the Commission has “clearly
set forth the ground for its departure from prior norms.” W.
States Petroleum Ass’n v. EPA, 87 F.3d 280, 284 (9th Cir.
1996).

   Petitioners assert that the Commission departed from its
prior precedent by denying them intervention despite the fact
that they raised NEPA claims and other environmental issues
in their motions to intervene. Petitioners cite three cases in
which the Commission granted late intervention to a movant
who filed its motion for late intervention raising issues about
a draft EA.14 See Cameron LNG, LLC, 118 F.E.R.C. ¶ 61,019
  14
     Although petitioners originally raised numerous Commission cases
allowing late intervention when movants raised “environmental issues,”
they later admitted in their reply brief that all but three of these cases
involved late intervention during the comment period for an EIS, which
falls under the automatic untimely intervention exemption of 18 C.F.R.
§ 380.10(a)(1)(i). See supra Part II.B.1.
                   CALIFORNIA TROUT v. FERC                  9193
(2007); Columbia Gas Transmission Corp., 113 F.E.R.C. ¶
61,118, 61,438 (2005); Pub. Util. Dist. No. 1 of Okanogan
County, 63 F.E.R.C. ¶ 61,337, 63,202 (1993). None of these
cited cases, however, indicate that the Commission here irra-
tionally departed from its prior precedent.

   [16] Two of the cited cases deal with intervention in a natu-
ral gas proceeding, and the Commission has concluded they
merit special consideration. In Cameron LNG, the Commis-
sion held that “[a]lthough . . . an environmental assessment
and not an environmental impact statement [was prepared],
and although [the movant] moved to intervene and filed com-
ments on the environmental assessment one day late, we will
grant [the movant’s] motion to intervene.” 118 F.E.R.C. ¶
61,019. But it did so reasoning that “[i]n the interest of giving
full consideration to requests for authorization of natural gas
projects, including those for LNG facilities, the Commission
has a liberal intervention policy in natural gas cases at this
particular stage of the proceeding, that is before an order on
the merits has been issued.” Id. (emphasis added); see also
Columbia Gas Transmission, 113 F.E.R.C. ¶ 61,118 (allow-
ing intervention in a natural gas case). Thus, both Cameron
LNG and Columbia Gas Transmission are easily distinguish-
able from this case—both involve “natural gas projects” that
the Commission has concluded involve special circumstances
not present here. Far from establishing a broad principle that
the Commission will allow untimely intervention whenever a
movant raises concerns with a draft EA, these cases establish
the opposite—that allowing such intervention is the exception
rather than the norm.

   Moreover, the petition to intervene in Cameron LNG was
filed only four months after the deadline for motions to inter-
vene and only one day after the deadline for comments on the
draft EA. Id. This is in contrast to the petitioners in this case,
who filed more than twenty months late. See Transok, L.L.C.,
89 F.E.R.C. ¶ 61,055, 61,186 (1999) (“Late intervention at the
early stages of a proceeding generally does not disrupt the
9194                  CALIFORNIA TROUT v. FERC
proceeding or prejudice the interests of any party . . . [so] the
Commission is more liberal in granting late intervention at the
early stages of a proceeding, but is more restrictive as the pro-
ceeding nears its end.” (footnote omitted)) (denying a motion
for intervention filed nine months after the deadline).

   [17] Although Public Utility District is not a natural gas
case, it too does not support petitioners’ claim that the Com-
mission departed from prior precedent. In Public Utility Dis-
trict, the Commission held in a very brief one-page order that
because it “[was] still in the process of considering [com-
ments filed in response to a draft EA], granting [certain orga-
nizations’] motions to intervene out of time [would] not
unduly delay or disrupt the proceeding or prejudice any party
to it.” 63 F.E.R.C. ¶¶ 61,337, 63,202. The Commission’s
decision (on a motion for rehearing) never mentioned whether
the movants had good cause to intervene—indeed, it did not
even consider whether there was good cause to intervene.
Here, unlike in Public Utility District, the Commission explic-
itly determined that the petitioners did not have good cause to
intervene: thus, it was not required, under Rule 214, to give
any weight to the fact that late intervention would not delay
the proceeding or otherwise prejudice the existing parties. The
Commission’s decision to treat petitioners differently based
on their lack of good cause is not “unreasonable, or plainly
inconsistent with the rationale” of Public Utility District. Cal.
Trucking, 900 F.2d at 213.15

   In its decisions denying intervention here, the Commission
cited numerous cases in which it found that similarly situated
persons lacked good cause to intervene late. See 122 F.E.R.C.
¶ 61,150 nn.5 & 7 (citing cases); 120 F.E.R.C. ¶ 61,057 nn.4
  15
     We note that even if Public Utility District were analogous to the facts
of this case, “one contrary precedent does not justify reversal of an agency
decision where the most recent line of authority is consistent.” Cal. Truck-
ing, 900 F.2d at 212 (citing NLRB v. Sunnyland Packing Co., 557 F.2d
1157, 1160-61 (5th Cir. 1977)).
                   CALIFORNIA TROUT v. FERC                    9195
& 5 (citing cases). These cases set out the Commission’s clear
policy of denying intervention to movants who knew (either
directly or constructively) that the Commission’s proceedings
could infringe on their interests, but “sat on their rights” and
waited for an adverse result before intervening. See, e.g.
Crown Landing LLC, 117 F.E.R.C. ¶ 61,209 (2006)
(“[Movant’s] argument that it discerned no need for a specific
intervention prior to issuance of the June 20 Order does not
demonstrate good cause for its late motion to intervene.”);
Erie Boulevard Hydropower, L.P., 117 F.E.R.C. ¶ 61,189
(2006) (“The fact that [a movant] only determined at an
extremely late date that it would like to compete for the proj-
ect site is not sufficient grounds to justify later intervention.”);
Fla. Gas Transmission Co., 100 F.E.R.C. ¶ 61,241 (2002)
(denying motion to intervene filed six months after the dead-
line because”[the movant] had or should have had knowledge
of [the subject matter of the proceeding]”).

   [18] All in all, the Commission has steadfastly and consis-
tently held that a person who has actual or constructive notice
that his interests might be adversely affected by a proceeding,
but who fails to intervene in a timely manner, lacks good
cause under Rule 214. See, e.g., Bradwood Landing LLC, 126
F.E.R.C. ¶ 61,035 (2009) (denying late intervention to
movant who claimed that scientific studies made it more
aware of its interests in the proceeding); Cent. Neb. Pub.
Power & Irrigation Dist., 125 F.E.R.C. ¶ 61,192 (2008)
(“The Commission expects parties to intervene in a timely
manner based on the reasonably foreseeable issues arising
from the applicant’s filings and the Commission’s notice of
proceedings.” (emphasis added)); Broadwater Energy LLC,
124 F.E.R.C. ¶ 61,225 (2008) (“Those entities with interests
they intend to protect are not entitled to wait until the out-
come of a proceeding and then file a motion to intervene once
they discover the outcome conflicts with their interests.”).
This is precisely the position in which petitioners find
themselves—each had actual or constructive notice that the
DWR license amendment might affect its interests, but neither
9196                 CALIFORNIA TROUT v. FERC
intervened until after the Commission issued its draft EA.
Because “good cause” is the principal factor the Commission
must point to when rejecting an untimely motion to intervene,
see supra Part II.B.2, this line of precedent applies directly to
petitioners’ motions. We cannot say that the Commission
deviated irrationally from its prior precedent in failing to
make an exception to its general rule for petitioners’ untimely
motions for intervention.

   The dissent argues that the Commission deviated from its
past precedent because “in hydroelectric cases, the Commis-
sion in practice does not impose a good cause requirement on
late intervention when there is no risk of prejudice.” Dissent-
ing Op. at 9200 (citing Alaska Power & Tel. Co., 98 F.E.R.C.
¶ 61,092 (2002)). The case cited by the dissent, however,
establishes nothing more than the entirely unremarkable prop-
osition that, in hydroelectric cases, “the Commission often has
made no finding of whether the movant has demonstrated
good cause for the late [intervention] request.” Alaska Power,
98 F.E.R.C. ¶ 61,092 (emphasis added).16 As we have noted,
the Commission is perfectly justified in deciding that it will
not consider good cause or the other discretionary factors per-
mitted by Rule 214. It is also perfectly justified, however, in
considering such factors and denying intervention when it
determines that a prospective intervener lacks good cause. See
18 C.F.R. § 385.214(b)(3) & (d)(1)(v). Where, as here, the
agency’s rule gives it the discretion either to consider or to
ignore certain factors, we would be remiss to eliminate this
discretion by requiring the agency to always ignore certain
factors just because it has “often” ignored these factors in the
past. The parity insisted on by the dissent would force the
  16
     We note that this statement in Alaska Power is dicta. Indeed, after
remarking that it had often ignored good cause in the past, the Commis-
sion decided to consider the factor in the case before it, and denied the
motion for untimely intervention. See 98 F.E.R.C. ¶ 61,092 (“There is
nothing in [movant’s request for late intervention] that makes any showing
of good cause for filing late, much less extraordinary grounds to justify
late intervention after issuance of a dispositive order.”).
                   CALIFORNIA TROUT v. FERC                  9197
Commission either to always consider or always ignore good
cause when considering motions for late intervention. We
cannot see that either of these outcomes is required by rule or
good administrative practice.

   [19] Finally, we observe that the Commission’s procedural
rules are no less important—and, therefore, no less deserving
of respect—than our own code of procedure. Such rules pro-
vide for orderly decisionmaking and constitute advance notice
of the process by which our institutions will conduct them-
selves. The petitioners knew the rules of the game and
assumed the risks of their decision not to intervene. The Com-
mission had no obligation, by statute or by rule, to provide
relief for petitioners’ failure to intervene in a timely fashion.

                               III

  For these reasons, CalTrout and FOR’s petitions for review
of the Commission’s decisions denying rehearing are
DENIED.



GOULD, Circuit Judge, dissenting:

   I respectfully dissent and would grant the petition because
the Commission has erected an unreasonably high barrier to
good cause for late intervention, and without explanation or
justification has departed from its own precedent of routinely
granting late intervention where there is no risk of prejudice.
In denying Petitioners’ motions for late intervention, the Fed-
eral Energy Regulatory Commission (“the Commission”) has
arbitrarily imposed a good cause requirement far more strin-
gent than indicated by analogous precedent and at odds with
the liberal standard it has applied consistently in similar cases.
Moreover, it should not go unnoticed that in denying leave to
intervene, the Commission has silenced any party wishing to
advance Petitioners’ environmental concerns. It is a salient
9198               CALIFORNIA TROUT v. FERC
fact that there are no parties remaining besides the dam opera-
tors and the FERC, and the Commission’s ruling prevents
anyone from challenging whether its decision to issue an
Environmental Assessment (“EA”) rather than a more com-
prehensive Environmental Impact Statement (“EIS”) violates
the National Environmental Policy Act. The Commission may
be happy as a clam to have no party able to challenge its judg-
ment, giving it in effect totally unconstrained discretion, but
in such a case the real loser is the public which will not have
environmental issues aired as they might have been raised by
an intervenor. The Commission does not explain why it has
departed from its prior precedent, and I choose not to be com-
plicit in its denial of late intervention, which impedes the pub-
lic’s interest in considering the environmental issues in this
case. This is not to say that the environmental considerations
favor one side or the other on the merits, but only that the
responsible Petitioners should not be shut out of the court-
house.

   The record shows that Petitioners’ intervention would not
offend any of the factors normally considered by the Commis-
sion in these cases, factors which together ask whether the
late intervention would create prejudice. See 18 C.F.R.
§ 385.214(d)(1). The majority does not dispute that Petition-
ers satisfy all three prejudice factors. Petitioners’ involvement
would not disrupt the proceedings in any way; no other party
represents the Petitioners’ interests; and there would be no
additional burden upon the existing parties.

    In any common sense assessment, there is strong cause for
the conduct of the Petitioners in seeking late intervention and
little justification on the other side for denying it. Petitioners
seek late intervention because 1) facts discovered intensified
the import of the issue to be challenged through intervention;
2) the Commission issued an EA rather than a more detailed
EIS, thereby eliminating what would have been an automatic
path for intervention; and 3) the Commission denied interven-
tion to another interested federal agency, the National Marine
                      CALIFORNIA TROUT v. FERC                          9199
Fisheries Service, which would have been in the position to
advance environmental issues, such as those raised by Peti-
tioners. There is little precedent available in our circuit con-
cerning the meaning of “good cause” which might inform our
assessment of the Commission’s interpretation of the good
cause requirement for late intervention. However, the phrase
“good cause” is used throughout our legal system, and often
it means little more than that there is a good reason for the
action proposed to be taken.1 Certainly, prior precedent does
not favor a rule that to have good cause to intervene one must
show that facts have developed permitting a new issue to be
raised that could not have been identified before those facts
surfaced.2 It should be sufficient if the new facts make the res-
  1
     For example, Federal Rule of Civil Procedure 6(b) provides that courts
“for good cause” may extend the time limits imposed by the rules of civil
procedure. Interpreting this language, courts have said that the good cause
standard and an extension “normally will be granted in the absence of bad
faith on the part of the party seeking relief or prejudice to the adverse
party.” 4B Charles Alan Wright, Arthur R. Miller & Edward H. Cooper,
Federal Practice and Procedure § 1154 (3d ed. 1998). Even when the
extension is sought after the time limit has expired, the good cause stan-
dard is satisfied merely upon a showing of excusable neglect. Fed. R. Civ.
P. 6(b)(2). Similarly, a liberal good cause standard applies when setting
aside an entry of default. Fed. R. Civ P. 55(c). Motions under this rule “are
frequently granted,” and good cause is generally found when “the court
finds that the default was not the result of gross neglect, that the nonde-
faulting party will not be substantially prejudiced by the reopening, and
the party in default has a meritorious defense.” 10A Wright, Miller &
Cooper § 2696 (footnotes omitted). Similarly, Black’s Law Dictionary
defines “good cause” as “a legally sufficient reason . . . . to show why a
request should be granted or an action excused,” and certainly that and
more was shown here. Black’s Law Dictionary 235 (8th ed. 2004).
   2
     The fact that good cause has been liberally interpreted in other contexts
does not necessarily control how good cause should be interpreted in
under the FERC’s late intervention regulations, 18 C.F.R. §§ 385.214(b)
& (d), for it is settled law that “[t]he same or similar words may have dif-
ferent meanings when used in different statutes motivated by different leg-
islative purposes.” Singh v. Ashcroft, 386 F.3d 1228, 1233 n.8 (9th Cir.
2004). Nonetheless, as Justice Jackson once observed, “the mere fact that
a path is a beaten one is a persuasive reason for following it.” Robert H.
Jackson, Full Faith and Credit—The Lawyer’s Clause of the Constitution,
45 Colum. L. Rev. 1, 26 (1945).
9200                 CALIFORNIA TROUT v. FERC
olution of an issue more important and enhance the impact of
a resolution on the parties and the public. Further, the prece-
dent that exists suggests that the meaning of good cause varies
depending on the degree of prejudice that would attend an
action, so that when prejudice is greater, the cause to justify
the action must be greater. The Commission’s own precedents
apply this type of sliding scale test and, as shown below, have
not insisted on a substantial showing of good cause when
there was no prejudice.

   The majority asserts, without citation to FERC case law,
that under FERC regulations a late petitioner must both show
good cause and prove that late intervention would not cause
prejudice. Op. at 9189-90. The Commission, however, has
interpreted its own regulations differently; it does not require
independent showings of both good cause and lack of preju-
dice. Rather, FERC precedent shows that the agency regularly
permits late intervention without requiring a showing of good
cause, when intervention would not cause prejudice.

   In my view, the Commission should have followed its pre-
cedent of Alaska Power & Telephone Co., 98 F.E.R.C.
¶ 61092 (2002), in which it said that it “has generally adopted
a liberal approach to late intervention in hydroelectric pro-
ceedings, if doing so will not delay the proceeding or result
in prejudice to other parties. In such cases, the Commission
often has made no finding of whether the movant has demon-
strated good cause for the late request.” Id. ¶ 61276.3 Alaska
Power & Telephone establishes that in hydroelectric cases,
the Commission in practice does not impose a good cause
requirement on late intervention when there is no risk of prej-
  3
    The Commission denied the late intervention request because it had
already issued a dispositive final order, after which “extraordinary
grounds” must be present to allow for late intervention because “the preju-
dice to other parties and burden on the Commission of granting late inter-
vention can be substantial.” Alaska Power and Tel., 98 F.E.R.C. ¶ 61277.
By contrast, here the Commission has not issued a final order, and no prej-
udice would result from allowing late intervention.
                     CALIFORNIA TROUT v. FERC                      9201
udice. This case is also a hydroelectric case,4 but here the
Commission without explanation departs from its “liberal
approach to late intervention in hydroelectric proceedings” by
imposing a rigorous “good cause” requirement on Petitioners
despite the lack of prejudice that would result from late inter-
vention. 98 F.E.R.C. at ¶ 61276.

   The cases cited by the majority further support the conclu-
sion that the Commission regularly does not require a mean-
ingful showing of good cause for late intervention when there
is no prejudice. See Op. at 9192-93. The majority asserts that
the liberal intervention policy announced in Cameron LNG,
LLC, 118 F.E.R.C. ¶ 61,019 (2007), and Columbia Gas
Transmission Corp., 113 F.E.R.C. ¶ 61,118, 61,438 (2005),
is limited only to natural gas cases. However, not only does
Alaska Power & Telephone apply this policy to hydroelectric
cases, but the Commission justifies its liberal late intervention
policy in cases involving natural gas not because of anything
specific to natural gas, but because “late intervention at the
early stages of natural gas certificate proceedings will neither
disrupt the proceedings nor prejudice the interests of any
other party.” Bradwood Landing LLC NorthernStar Energy
LLC, 126 F.E.R.C. ¶ 61035 (2009).

   Public Utility District No. 1 of Okanogan County, 63
F.E.R.C. ¶ 61,337, 63,202 (1993), which is not a natural gas
case, further undercuts the Commission’s decision against
Petitioners because there too the Commission allowed a late
intervention after determining that it would not disrupt pro-
ceedings or cause prejudice. The majority acknowledges that
in Public Utility District the Commission did not explicitly
impose a separate good cause requirement. The most natural
reading of Public Utility District, Alaska Power & Telephone,
  4
    This case concerns water flow through a dam and involves a license
issued under the Federal Power Act. Such licenses permit the operation of
dams and other hydroelectric projects. See 16 U.S.C. § 797(e); Op. at
9174.
9202                   CALIFORNIA TROUT v. FERC
and the natural gas cases, one that unifies them into a consis-
tent standard, is that the Commission does not require any
substantial showing of good cause when there is no evidence
of prejudice or disruption.5

   I conclude that the Commission should have allowed Peti-
tioners to intervene both because good cause was shown for
a late intervention, and because intervention was permissible
in any event under the Commission’s usual policy of dispens-
ing with the good cause requirement when, as here, there was
no risk of prejudice or disruption to other parties. Here, how-
ever, the Commission without explanation departed from its
own precedent and required Petitioners to make a substantial
showing of good cause. This deviation was an arbitrary depar-
ture from prior agency rules of decision and is prohibited by
our precedent. See Cal. Trucking Ass’n v. Interstate Com-
merce Comm’n, 900 F.2d 208, 212 (9th Cir. 1990) (stating
that an agency “may not depart, sub silentio, from its usual
rules of decision to reach a different, unexplained result in a
single case” (quotation omitted)). By denying Petitioners’
attempt to intervene, the Commission has ensured that no
  5
    The majority contends that the Commission “has steadfastly and con-
sistently held” that a petitioner who intervenes late despite having notice
that might justify an earlier intervention lacks good cause. Op. at 9195.
However, in each of the six cases the majority cites for this claim, the
Commission also determined that late intervention would cause prejudice
or that another party already represented the late petitioner’s interests. See,
e.g., Bradwood Landing LLC, 126 F.E.R.C. ¶ 61,035 (2009) (“Allowing
late intervention at this point in the proceeding brings very little benefit
to the proceeding and potentially would create prejudice and additional
burdens on the Commission, other parties, and the applicants.”); Cent.
Neb. Pub. Power & Irrigation Dist., 125 F.E.R.C. ¶ 61,192 (2008) (deny-
ing intervention after the Commission issued a dispositive order because
“[o]nce a dispositive order has been issued in a proceeding . . . the preju-
dice to other parties and the burden on the Commission of granting late
intervention are substantial”); Crown Landing LLC, 117 F.E.R.C. ¶
61,209 (2006) ( “[Late Petitioner] claims no intention to inject any new
argument into this proceeding beyond those offered by [an existing
party].”).
                  CALIFORNIA TROUT v. FERC               9203
group can challenge in court whether the Commission’s
actions in this case comply with federal environmental law.
There is no good reason why those who wish to advance
important environmental issues should be practically silenced,
in the sense that they have submitted materials for the agency
to review but are left with no court process for an appeal of
the decision of the Commission. I respectfully dissent and
would hold that the Commission acted in an arbitrary and
capricious manner by failing to follow its own precedent.
