FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

NATIVE ECOSYSTEMS COUNCIL;               
ALLIANCE FOR THE WILD ROCKIES
WILDWEST INSTITUTE,
               Plaintiffs -Appellants,
                  v.
TOM TIDWELL, in his official
capacity as Northern Region
Regional Forester; BRUCE RAMSEY,
in his official capacity as
Supervisor of the Beaverland-
Deerlodge National Forest; MARK
PETRONI, in his official capacity as
                                         
District Ranger of the Madison
River Ranger District of the
Beaverhead-Deerlodge National
Forest; UNITED STATES FOREST
SERVICE, an agency of the U.S.
Department of Agriculture,
               Defendants-Appellees,
MADISON COUNTY; BEAVERHEAD
COUNTY, MONTANA,
  Defendants-intervenors-Appellees,
                                         




                              3705
3706         NATIVE ECOSYSTEMS COUNCIL v. TIDWELL



SITZ ANGUS RANCH; GARY L.             
CLARK; MOOSE CREEK GRAZING
ASSOCIATION; MAX L. ROBINSON,               No. 06-35890
SR.; MAX J. ROBINSON, JR.;
MONTANA STOCKGROWERS                         D.C. No.
                                          CV-04-00127-DWM
ASSOCIATION; MONTANA WOOL                     OPINION
GROWERS ASSOCIATION,
             Intervenors-Appellees.
                                      
         Appeal from the United States District Court
                 for the District of Montana
       Donald W. Molloy, Chief District Judge, Presiding

                  Argued and Submitted
           November 19, 2008—Seattle, Washington

                     Filed March 9, 2010

 Before: Alex Kozinski, Chief Judge, Betty B. Fletcher, and
           Johnnie B. Rawlinson, Circuit Judges.

                Opinion by Judge Rawlinson;
               Dissent by Chief Judge Kozinski
3710        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL




                         COUNSEL

Thomas J. Woodbury, Missoula, Montana, on behalf of
plaintiff-appellants Native Ecosystems Council, Alliance for
the Wild Rockies, and Wildwest Institute.

Robert H. Oakley, Washington, D.C., on behalf of defendant-
appellees Tom Tidwell, Bruce Ramsey, Mark Petroni, and the
United States Forest Service.

John E. Bloomquist, Helena, Montana, on behalf of
intervenor-appellees Sitz Angus Ranch, Gary L. Clark,
Moorse Creek Grazing Association, Max L. Robinson Sr.,
Max L. Robinson, Jr., Montana Stockgrowers Association,
and Montana Wool Growers.


                         OPINION

RAWLINSON, Circuit Judge:

   Plaintiffs-Appellants Native Ecosystems Council, Alliance
for the Wild Rockies, and Wildwest Institute (collectively
NEC) appeal the district court’s summary judgment in favor
of Defendants-Appellees Tom Tidwell, Bruce Ramsey, Mark
Petroni, and the United States Forest Service (collectively
Forest Service); Defendants-Intervenors-Appellees Madison
County and Beaverhead County; and Intervenors-Appellees
Sitz Angus Ranch, Gary L. Clark, Moose Creek Grazing
Association, Max L. Robinson Sr., Max L. Robinson, Jr.,
Montana Stockgrowers Association, and Montana Wool
Growers Association; and (collectively Intervenors-
Appellees). NEC argues that the district court erred in finding
              NATIVE ECOSYSTEMS COUNCIL v. TIDWELL                   3711
that Forest Service approval of a project to update grazing
allotments in the Beaverhead-Deerlodge National Forest com-
plies with the Forest Service’s obligation to ensure species
diversity as required under the National Forest Management
Act (NFMA). It also contends that the district court erred in
concluding that the Environmental Assessment undertaken by
the Forest Service project satisfied the National Environmen-
tal Policy Act (NEPA). We agree with NEC on both counts.
Because the Forest Service’s environmental assessment was
based on a nonexistent management indicator species (MIS),
its habitat proxy analysis was not reliable. The Forest Service
also failed to take the requisite “hard look” at the project as
required by NEPA. We therefore reverse the district court’s
summary judgment in favor of the Forest Service, and remand
for further proceedings consistent with this opinion.

I.       BACKGROUND

     A.   Project area and Allotment Management Plan
          (AMP) Proposal1

   The Antelope Basin/Elk Lake project area is in the
Beaverhead-Deerlodge National Forest (BDNF) in Southwest
Montana. The project area is approximately 48,000 acres and
forms the southeast portion of the Gravelly Mountain Range.
Most of the project area is open, mountain sagebrush/
grasslands with some scattered timber along streams.
     1
    An AMP is “a document, prepared in consultation with lessees or per-
mittees, that applies to livestock operations on public lands, and (1) pre-
scribes the manner and extent to which livestock operations will be
conducted in order to meet multiple use, sustained-yield, economic, and
other needs and objectives, (2) describes range improvements to be
installed and maintained, and (3) contains such other provisions relating
to livestock grazing and other objectives found by the Secretary to be con-
sistent with the provisions of [the Federal Land Policy Management Act].”
Antelope Basin/Elk Lake AMP Updates, Environmental Assessment,
Revised (Environmental Assessment), Chapter 1, p. 2 (December 2002).
3712          NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
   Three Forest Service activities have most affected the sage-
brush ecosystem in the project area: 1) herbicide application
to control sagebrush densities;2 2) burning to control sage-
brush densities;3 and 3) livestock grazing. Sheep and cattle
have grazed a majority of the project area over the past cen-
tury.

   As part of a settlement agreement in an unrelated case, the
Forest Service agreed to a schedule for completing NEPA
environmental analyses and decisions for the authorization of
livestock grazing and associated resource protection mea-
sures. The Environmental Assessment at issue in this case
contains the NEPA analysis underlying some of the livestock
allotments listed in the agreed-upon schedule.

   The project area was divided into eleven grazing allot-
ments. The project proposed updating AMPs for these eleven
allotments. The updated allotments would determine “where
livestock can graze, when grazing would occur and what spe-
cific guidelines would be established to regulate the intensity
of grazing.” As of the time of the proposal, the prior AMPs
for all eleven allotments were ten years or older.

   The proposal specifically identified the goals established in
the BDNF Land Resource Forest Plan (Forest Plan)4 which
governed the proposed project. These goals included main-
taining a sufficient number of diverse habitats to support
native wildlife and providing opportunities for grazing by
domestic livestock without compromising extant forest
resources. The proposal also stated that no further “sage brush
control measures” such as burning or herbicides are contem-
plated in the project area in the near future.
  2
     From 1960 to 1974, approximately 5865 acres were treated with herbi-
cides.
   3
     6,491 acres were burned from 1982-1988, and 6,476 acres from 1992
- 2000.
   4
     The NFMA requires the Forest Service to develop a forest plan for
each unit of the National Forest System. See 16 U.S.C. § 1604(a).
               NATIVE ECOSYSTEMS COUNCIL v. TIDWELL                   3713
   The Forest Service prepared an initial Environmental
Assessment for the proposed AMPs, and issued a revised
Environmental Assessment after receiving public comments.
The revised Assessment specifically addressed concerns
regarding the project’s impact on sage grouse, as well as other
sagebrush habitat obligates. The Environmental Assessment
considered three options for updating the AMPs: (1) Alterna-
tive A, which continued the status quo; (2) Alternative B, the
preferred alternative, which modified the AMPs to protect
riparian habitat while allowing grazing;5 and (3) Alternative
C, which banned grazing altogether. The United States Fish
and Wildlife Service issued a Biological Evaluation conclud-
ing that adoption of the preferred alternative was not likely to
adversely affect or jeopardize the continued existence of any
listed species.

   In November, 2003, District Ranger Mark Petroni released
a Decision Notice and Finding of No Significant Impact (DN/
FONSI) reflecting the administrative decision to proceed with
Alternative B. The DN/FONSI concluded that the project was
not a major federal action with significant effect on the qual-
ity of the human environment, and therefore no Environmen-
tal Impact Statement (EIS) was warranted under NEPA.
  5
    Alternative B proposed revising the AMPs in numerous ways: reducing
animal unit months from 11,225 to 10,453; eliminating the Elk Mountain
allotment; changing boundaries to create a new, Two Drinks allotment;
excluding livestock from a portion of Elk Lake and all of Elk Springs
Creek; limiting allowable upland forage utilization to fifty percent; limit-
ing riparian forage to fifty-five percent; possibly eliminating livestock
from the upper regions of Narrows Creek; and constructing structural
improvements as needed. The proposal included construction of 6.75
miles of new fence, a new reservoir, 26 new water troughs, 5.75 miles of
new pipeline, and relocating 5 miles and removing 2 miles of existing
fence. For all allotments, livestock would be moved to the next pasture or
removed from the allotment once certain utilization thresholds were met.
3714           NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
  B.    The Sage Grouse

   To facilitate its goals of wildlife diversity, the governing
Forest Plan designates certain wildlife as “management indi-
cator species” (MIS). These species are monitored to measure
the effect of various activities on corresponding wildlife habi-
tats. The objective of monitoring the MIS is to ensure the via-
bility of wildlife species existing in the forest. The sage
grouse is one such MIS for the sagebrush wildlife habitat.

   The sage grouse is entirely dependent on sagebrush eco-
systems. The sage grouse population in southwestern Mon-
tana has trended downward for the past decade. There are no
identified active sage grouse leks in the project area.6 The
closest known active lek is approximately eleven miles west
of the project area. See A Review of USFS Management Activ-
ities and Their Relationship to Sage grouse in the Antelope
Basin/Elk Lake Area of Southwestern Montana, J.W. Con-
nelly (September, 2004) (hereinafter, “Connelly Review”). In
the past fifteen years, only two possible sage grouse sightings
have been noted in the project area.

  Approximately 21,000 acres (40% of the project area) are
considered to have potential sage grouse habitat. Only 1,900
acres are considered to have potential sage grouse nesting and
early brood rearing habitat.

  C.    Supplemental Information Report

   In December 2004, the Forest Service issued a Supplemen-
tal Information Report (“SIR”) concerning the sage grouse,
  6
   A lek is a “breeding display site[ ], typically occurr[ing] in open areas
surrounded by sagebrush. Male sage grouse apparently construct leks “op-
portunistically at sites within or adjacent to potential nesting habitat.”
Guidelines to Manage Sage grouse Populations and Their Habitats, John
W. Connelly, Michael A. Schroeder, Alan R. Sands and Clait E. Braun,
Wildlife Society Bulletin, Vol. 28, p. 970 (2000) (hereinafter, “Connelly
Guidelines”).
            NATIVE ECOSYSTEMS COUNCIL v. TIDWELL         3715
and specifically discussed information that had been released
after the Environmental Assessment. The SIR evaluated the
findings of three primary works as they related to the pro-
posed project: (1) Conservation Assessment of Greater Sage
grouse and Sagebrush Habitats, J.W. Connelly, S.T. Knick,
M.A. Schroeder and S.J. Stiver, Western Association of Fish
and Wildlife Agencies (June, 2004) (hereinafter, “Conserva-
tion Assessment”); (2) Management Plan and Conservation
Strategies for Sage grouse in Montana - Final Draft Plan,
Montana Sage grouse Work Group (March, 2004); and (3)
habitat modeling completed in 2004 by the Forest Service sur-
veying active and inactive sage grouse leks in the vicinity of
the project area.

   To inform its analysis, the Forest Service requested that
Connelly undertake a site-specific review of the project area
in light of the new information concerning the sage grouse.
Connelly’s findings were documented in the September, 2004
Connelly Review. The review concluded that the Environmen-
tal Assessment’s conclusions were “reasonable and supported
by the available evidence. Effects to sage grouse resulting
from project implementation will likely be minimal.”

  After considering the newly available information and the
Connelly Review, the District Ranger determined that the
Environmental Assessment’s conclusions remained accurate.
The SIR retained the determination of minimal effects to sage
grouse from project implementation, and did not recognize a
need to further revise the Environmental Assessment or pre-
pare an EIS.

  D.   Procedural Background

  NEC filed an administrative appeal of the District Ranger’s
decision that no EIS was warranted. Then-Regional Forester,
Abigail Kimbell, upheld the District Ranger’s decision.
3716          NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
   After NEC filed a complaint in district court seeking
declaratory and injunctive relief, each party moved for sum-
mary judgment. The district court granted summary judgment
to the Forest Service and the Intervenors. NEC filed a timely
appeal, invoking our jurisdiction under 21 U.S.C. § 1291.7

II.    STANDARDS OF REVIEW

   “We review de novo the district court’s grant of summary
judgment.” Lands Council v. Martin, 

, 1225
(9th Cir. 2008) (citation omitted). We review agency deci-
sions for compliance with the NFMA and NEPA under the
Administrative Procedure Act (APA). See Envtl. Prot. Info.
Ctr. v. U.S. Forest Serv., 

, 1008 (9th Cir. 2006).
The APA directs us to “hold unlawful and set aside agency
action, findings, and conclusions found to be . . . arbitrary,
capricious, an abuse of discretion, or otherwise not in accor-
dance with law.” 5 U.S.C. § 706(2)(A). “Review under the
arbitrary and capricious standard is narrow and we do not sub-
stitute our judgment for that of the agency.” Tucson Herpeto-
logical Soc’y v. Salazar, 

, 875 (9th Cir. 2009)
(citation, alterations and internal quotation marks omitted).
“The [agency] has an obligation, however, to state a rational
connection between the facts found and the decision made.”

internal quotation marks omitted).

III.   DISCUSSION

  A.    Compliance with the NFMA

  [1] “The NFMA sets forth the statutory framework and
  7
    On appeal, NEC does not challenge the district court’s conclusion that
it failed to exhaust its administrative remedies with respect to its argu-
ments regarding the northern goshawk, flammulated owl, grayling, lake
trout, and boreal toad. Nor does NEC renew its claims under the Clean
Water Act. Accordingly, we consider these arguments waived. See Eng v.
Cooley, 

, 1072 (9th Cir. 2009).
               NATIVE ECOSYSTEMS COUNCIL v. TIDWELL                   3717
specifies the procedural and substantive requirements under
which the Forest Service is to manage National Forest System
lands.” Lands Council v. McNair, 

, 988 (9th Cir.
2008) (en banc). Procedurally, “all management activities
undertaken by the Forest Service must comply with the forest
plan, which in turn must comply with the [NFMA].” Idaho
Sporting Cong., Inc. v. Rittenhouse, 

, 962 (9th
Cir. 2002). Substantively, the NFMA also places a duty on the
Forest Service to “provide for diversity of plant and animal
communities based on the suitability and capability of the
specific land area . . . ” 16 U.S.C. § 1604(g)(3)(B). “In order
to ensure compliance with the forest plan and the [NFMA],
the Forest Service must conduct an analysis of each ‘site spe-
cific’ action, such as a timber sale, to ensure that the action
is consistent with the forest plan.” Idaho 

(citation omitted).

   [2] Regulations implementing the statute, in effect at the
time the Forest Service issued its final decision, required the
Forest Service to manage fish and wildlife habitat “to main-
tain viable populations of existing . . . species.” 36 C.F.R.
§ 219.19 (2000). To ensure population viability and monitor
the effects of management, the regulations mandated the iden-
tification and selection of a management indicator species
(MIS). See 

The regulations also provided
that “[p]opulation trends of the management indicator species
will be monitored and relationships to habitat changes deter-
mined . . . ” 

  The Forest Plan incorporated specific species diversity
maintenance goals, explaining that:
  8
    This regulation is no longer in effect, as “new regulations have elimi-
nated the MIS concept . . . ” Envtl. Prot. Info. 

n.8;
see also 36 C.F.R. § 219.16 (2008). However, the Forest Service is “re-
quired to comply with the regulations and forest plan in place at the time
of its decision.” Envtl. Prot. Info. 

n.8.
3718        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
    Maintenance and enhancement of wildlife habitat
    has high priority in the management of the Forest.
    Viable populations of all existing wildlife species
    will be maintained by providing a diversity of habi-
    tats throughout the Forest. Wildlife indicator species
    have been identified and will be monitored to ensure
    that assumptions concerning the effects of manage-
    ment activities on wildlife habitat and populations
    are appropriate.

United States Forest Service, Forest Plan, Beaverhead
National Forest (Forest Plan), 1986, p. II-3. The Forest Plan
designated the sage grouse as the MIS for sagebrush commu-
nities. The Forest Plan contemplated monitoring the sage
grouse as an indicator species “to measure the effect of man-
agement activities on representative wildlife habitats with the
objective of ensuring that viable populations of existing native
and desirable non-native vertebrate species are maintained.”

its designation as an MIS, the sage grouse is
virtually non-existent in the project area. Because actual sage
grouse population data is unavailable, the Environmental
Assessment looked to the sagebrush habitat to assess viability
for the sagebrush obligate species. This is known as the
“proxy-on-proxy” approach, whereby the Forest Service
“use[s] habitat as a proxy to measure a species’ population,
and then [ ] use[s] that species’ population as a proxy for the
population of other species.” 

n.10.

   [4] The proxy-on-proxy approach effectively allows the
Forest Service “to avoid studying the population trends of the
Indicator Species by using Indicator Species habitat as a
proxy for Indicator species population trends.” Lands Council
v. Powell, 

, 1036 (9th Cir. 2005), as amended.
Use of this approach however, is appropriate “only where
both the Forest Service’s knowledge of what quality and
quantity of habitat is necessary to support the species and the
               NATIVE ECOSYSTEMS COUNCIL v. TIDWELL                     3719
Forest Service’s method for measuring the existing amount of
that habitat are reasonably reliable and accurate.” Native Eco-
systems Council v. United States Forest Service, 

, 1250 (9th Cir. 2005). Underlying the proxy-on-proxy
approach is the “assum[ption] that maintaining the acreage of
habitat necessary for survival would in fact assure a species’
survival.” Envtl. Prot. Info. 

(citation
and internal quotation marks omitted). Thus, “[t]he test for
whether the habitat proxy is permissible . . . is whether it rea-
sonably ensures that the proxy results mirror reality.” Gifford
Pinchot Task Force v. United States Fish and Wildlife Ser-
vice, 

, 1066 (9th Cir. 2004) (citations and inter-
nal quotation marks omitted).

   [5] The proxy-on-proxy approach’s reliability is question-
able where the MIS is absent from the project area.9 Regard-
less of whether the Forest Service’s methodology comports
with established scientific standards, the habitat proxy “does
not reasonably ensure viable populations of the species at
issue,” when almost no sage grouse have been seen in the
project area for fifteen years. Idaho 

.
There is simply no basis to evaluate the Forest Service’s
assertion that the sagebrush habitat is sufficient to sustain via-
ble sage grouse populations when sage grouse cannot be
found in the project area. Therefore, the Forest Service cannot
reasonably argue that the proxy-on-proxy approach allows it
to avoid separately monitoring sage grouse population trends,
as sage grouse are its chosen MIS. See 

    We have recognized that “monitoring difficulties do not render a
habitat-based analysis unreasonable, so long as the analysis uses all the
scientific data currently available.” 

(citation
omitted). Here, however, the government does not cite any “monitoring
difficulties” that prevent detection of the sage grouse. Cf., 

although surveys did not locate any animal, the Forest Service’s method
for detecting the bird may have been flawed). In this case, the Forest Ser-
vice resorted to a habitat analysis, not because monitoring the sage grouse
was difficult, but because there were admittedly no sage grouse in the
project area to monitor.
3720        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
1036 (noting that the proxy-on-proxy result is aimed at estab-
lishing “species population trends”) (emphasis added). This is
especially true where, as here, the forest plan requires moni-
toring of the MIS. See Earth Island Institute v. USFS, 

, 1175-76 (9th Cir. 2006) (rejecting the use of habi-
tat monitoring where the forest plan required population mon-
itoring), abrogated on other grounds by Winter v. Natural
Res. Def. Council, Inc., ___ U.S. ___, 

, 375
(2008).

   We do not share our dissenting colleague’s perception that
the Forest Service can meet its obligations to the environment
by naming a virtually non-existent species to serve as a proxy
for critical habitat in the targeted area. Far from usurping the
agency’s role, our opinion holds the agency to its statutory
responsibility to fully study the effects of the planned agency
action, and “to maintain viable populations of existing . . .
species.” 36 C.F.R. § 219.19 (emphasis added). It is unfath-
omable how the Forest Service could meet its responsibility
to maintain existing species by selecting as a proxy a species
that is virtually non-existent in the targeted area. A “report of
two sage grouse being taken illegally from the project area [of
48,000 acres] in 2002,” see Dissenting Opinion, p. 3730, just
doesn’t cut it.

   Our colleague in dissent also criticizes this result as under-
mining the Forest Service’s ability to develop one integrated
plan for each unit of the National Forest System. See Dissent-
ing Opinion, pp. 3731-32. The law does not support this con-
tention. The Forest Service is bound to assess proposed
actions on a “site specific” basis for compliance with the For-
est Plan and NFMA. See 18 U.S.C. § 1604(i); see also Inland
Empire Pub. Lands Council v. U.S. Forest Serv., 

,
757 (9th Cir. 1996) (explaining that both the Forest Plan and
site-specific project stages must fully comply with the
NFMA); Or. Natural Desert Ass’n v. U.S. Forest Serv., 

, 980 (9th Cir. 2006) (explaining that AMPs are plans
for specific allotments). If the Forest Service decided to select
            NATIVE ECOSYSTEMS COUNCIL v. TIDWELL           3721
a project site consisting of the head ranger’s backyard, see
Dissenting Opinion, p. 3732, it must indeed analyze that par-
ticular site to determine the effects of the proposed action. If
the MIS were absent from that site, it is difficult to see how
an assessment of the MIS could demonstrate that the proposed
action at that site complied with either the NFMA or a Forest
Plan based on monitoring of the MIS.

   Indeed, the record strongly suggests that the Forest Ser-
vice’s methodology in applying the proxy-on-proxy approach
is flawed. In preparing its Biological Evaluation, the Forest
Service expressly relied on the Connelly Guidelines in deter-
mining whether sage grouse habitat was sufficient. However,
at least some of these guidelines assume the presence of birds
as indicators of habitat health. See Connelly Guidelines, pp.
975-76. The Connolly Guidelines specifically note that “quan-
titative data from population and habitat monitoring are nec-
essary to implement the guidelines correctly.” 

975
(emphasis added). Moreover, in the Conservation Assessment,
p. 4-15, generated after the Connelly Guidelines, Connelly
and his co-authors recognized that “populations of sage-
grouse have been extirpated at places throughout their former
range concomitant with habitat loss and degradation, so that
the species’ current distribution is less closely aligned with
that of sagebrush.” (citation omitted). Thus, the very guide-
lines used by the Forest Service militate against the Forest
Service’s assertion that evaluation of the sagebrush habitat in
the complete absence of a sage grouse population meets its
obligation under the NFMA to ensure population viability of
the sage grouse and other sagebrush obligates.

   In response to the argument that population monitoring is
essential to a proper analysis of the project under the NFMA,
the Forest Service repeatedly argues that population monitor-
ing is outside the scope of the project, which is meant solely
to consider updating grazing allotment protocols. However, to
meet NFMA requirements, the Forest Service needed to con-
sider and preserve the project species. As the Conservation
3722        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
Assessment, p. 1-3, noted, “land-use perspectives have goals
to maximize a particular function that may have objectives
competing with other resource use. For example, evaluation
of sagebrush communities primarily based on their ability to
provide forage for livestock may result in extensive alter-
ations that are unsuitable for greater sage grouse and other
species dependent on sagebrush habitats.” (citations omitted).

   [6] Because the habitat proxy failed to track the MIS popu-
lation, the proxy-on-proxy approach was unreliable in ensur-
ing overall diversity in this case. In applying the proxy-on-
proxy approach to evaluate whether the project complied with
the Forest Service’s duty to ensure wildlife diversity, the For-
est Service did not adequately consider evidence that, despite
the Forest Service’s asserted compliance with the Connelly
Guidelines, the sage grouse population continued to trend
downward over several decades. This omission on the part of
the Forest Service would suggest that the agency has “failed
to consider an important aspect of the problem,” or has
offered an explanation for its decision that runs counter to the
evidence in the record, and its decision is therefore arbitrary
and capricious. Motor Vehicle Mfrs. Assn., Inc. v. State Farm
Mut. Auto. Ins. Co., 

, 43 (1983).

   [7] The record further suggests that in addition to failing to
monitor and incorporate sage grouse population data in its
analysis, the Forest Service failed to adhere to the Connelly
Guidelines in assessing the sagebrush habitat. In conducting
its environmental analysis, the Forest Service failed to iden-
tify the nesting habitat in the project area later noted by Con-
nelly and addressed in the Connelly Review. The
Environmental Assessment stated that there are no known
nesting grounds in the project area, noting that “[n]esting con-
ditions . . . are not met within the project area during the sage
grouse nesting season (May to mid-June).” The Forest Service
concluded that the absence of nesting habitat “appears to be
limited by growing conditions and plant physiology, not by
past years’ cattle grazing . . .” The Forest Service ostensibly
              NATIVE ECOSYSTEMS COUNCIL v. TIDWELL                3723
relied upon the Connelly Guidelines in reaching this conclu-
sion. However, Connelly concluded that there were at least
1900 acres of nesting habitat in the project area. See Connelly
Review pp. 11-12. Indeed, Connelly specifically stated that
this area has “relatively high canopy coverage of grasses and
forbs with adequate height for nesting habitat.” Connelly
Review p. 12. “In short,” he concluded, “the area seems to
have all the characteristics associated with productive sage
grouse breeding habitat.” 

Connelly Guidelines).

   [8] The discrepancy between the Forest Service’s conclu-
sions and Connelly’s conclusions, where both ostensibly
applied the Connelly Guidelines, strongly suggests that the
Forest Service’s method of measuring the sagebrush habitat is
neither reasonably reliable nor accurate. See Native Eco-

. This flaw in the Forest Service’s
methodology further undermines the reliability of the Forest
Service’s use of the proxy-on-proxy approach. See 

(holding that the proxy-on-proxy approach
failed to comply with NFMA where habitat analysis was
flawed).

   The Forest Service’s analysis of the 1900 acres of breeding
habitat also contradicted Connelly’s view of whether cattle
grazing would interfere with the sage grouse breeding period.
The AMPs would allow cattle grazing in the area as soon as
June 1. The Forest Service noted in the Environmental
Assessment that the nesting season usually takes place from
May to mid-June. In the SIR, the Forest Service concluded
that the grazing season was compatible with sage grouse
breeding, because cattle generally did not graze in that region
until late June.10 However, the Connelly Review referenced
scientific studies suggesting that “[t]he hatching period for
most sage grouse populations generally occurs from mid-May
  10
    The SIR also inaccurately described the nesting season as occurring
in April and May, contrary to the statement in the Environmental Assess-
ment.
3724        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
until early June.” Connelly Review, p. 4 (emphasis added).
Connelly stated that “there is some evidence that grouse using
high elevation area may not begin nesting until mid-May.” 

(citation omitted). Connelly cited evidence
that “5 of 6 nesting hens (83%) initiated nesting between 10
May and 17 June in the Sawtooth Valley of central Idaho,” an
area with a similar elevation range as the project area. 

He noted that yet another scientist “also
reported that sage grouse may nest well into June . . . ” 

   Our colleague in dissent does not deny that inconsistencies
exist between the Forest Service’s analysis and Dr. Connel-
ly’s conclusions. Instead, the dissent takes refuge in Dr. Con-
nelly’s fuzzy assurance that the contemplated actions “are
generally consistent with the current sage-grouse management
guidelines.” Dissenting Opinion, p. 3733 (quoting Connelly
Review). However, that general observation in no way erases
the specific discrepancies between Dr. Connelly’s studies and
the Forest Service’s analysis.

   [9] In sum, under the facts of this case, where the MIS
population has consistently declined and has not appeared in
the Project Area in nearly two decades, and where the agen-
cy’s analysis conflicted with that of the scientific experts, the
Forest Service’s use of the proxy-on-proxy approach to ensure
viability of sagebrush obligates did not comply with the dic-
tates of the NFMA to monitor population trends of the sage
grouse as the selected MIS. See Earth Island 

. The District Ranger’s determination that the
project would have minimal effects on the sage grouse was
not derived from a reliable methodology. See 

(holding that the Forest Service acted arbitrarily and capri-
ciously by relying on inadequate habitat monitoring of the
MIS). Accordingly, we reverse the district court’s grant of
summary judgment in favor of Defendants on the Plaintiffs’
NFMA claim.
             NATIVE ECOSYSTEMS COUNCIL v. TIDWELL            3725
  B.   Compliance with NEPA

   [10] “In contrast to NFMA, NEPA exists to ensure a pro-
cess, not to mandate particular results.” Neighbors of Cuddy
Mountain v. Alexander, 

, 1063 (9th Cir. 2002)
(citation omitted). “NEPA requires a federal agency ‘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.’ ” Ctr. for
Biological Diversity v. Nat’l Highway Traffic Safety Admin.,

, 1185 (9th Cir. 2008) (citations and alteration
omitted).

   As a preliminary step, an agency may prepare an environ-
mental assessment “in order to determine whether a proposed
action may significantly affect the environment . . . ” 

alteration and internal quotation marks omitted). “If the
agency concludes in the [environmental assessment] that there
is no significant effect from the proposed project, the federal
agency may issue a finding of no significant impact
(‘FONSI’) in lieu of preparing an EIS.” Native Ecosystems

(citations omitted). “If an agency
decides not to prepare an EIS, it must supply a convincing
statement of reasons to explain why a project’s impacts are
insignificant. The statement of reasons is crucial to determin-
ing whether the agency took a hard look at the potential envi-
ronmental impact of a project.” Center for Biological

(citations and internal quotation
marks omitted).

   [11] As discussed above, the Forest Service’s use of the
nonexistent sage grouse as an MIS to assess the project’s
impact on all sagebrush species’ diversity was flawed. As a
result, its overall study of the sage grouse habitat throughout
the Environmental Assessment was similarly deficient. Just as
the methodology applied by the Forest Service to measure
habitat conditions did not meet the NFMA requirements, its
flawed methodology in the complete absence of a sage grouse
3726        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
population does not constitute the requisite “hard look” man-
dated by NEPA. See Native Ecosystems Council v. USFS, 

, 964-65 (9th Cir. 2005) (recognizing that the Forest
Service’s reliance on incorrect assumptions and/or data vio-
lated NFMA and did not meet the agency’s obligation to take
a “hard look” under NEPA).

  We cannot say that the results of the Environmental
Assessment would have differed if an appropriate MIS for
sagebrush obligates had been selected. In the absence of that
analysis, we reverse and remand for the Forest Service to
undertake a new or revised Environmental Assessment. See
Earth Island 

(reversing and
remanding due to defects in the Forest Service analysis).

   Finally, we note that the Forest Service’s decision not to
supplement the Environmental Assessment following the
Connelly Review’s discussion of the 1900 acres of nesting
habitat fails to comply with the agency’s obligations to sup-
plement an environmental assessment when “[t]here are sig-
nificant new circumstances or information relevant to
environmental concerns and bearing on the proposed action or
its impacts.” 40 C.F.R. § 1502.9(c)(1)(ii); see Klamath Siski-
you Wildlands Ctr. v. Boody, 

, 560 (9th Cir.
2006).

   The Forest Service’s justifications for its decision not to
further revise the Environmental Assessment are unpersua-
sive. Although the Forest Service suggests that it made no
“estimate of the amount of breeding/nesting habitat in the
allotments[,]” the record clearly reflects otherwise. The Forest
Service in fact analyzed the impact of the project on late
brood-rearing habitat. This approach was taken precisely
because the sagebrush habitat in the project area was “not
considered to be nesting habitat.” However, Connelly’s
assessment of the project specified that the “[p]roposed man-
agement will likely have little effect on this habitat unless
offtake results in average herbaceous height <18 cm in mid to
             NATIVE ECOSYSTEMS COUNCIL v. TIDWELL            3727
late June . . . ” Connelly Assessment p. 13. The Environmental
Assessment, predicated on the assumption that no nesting
habitat existed in the project area, did not address anticipated
offtake results under the project at all. Nor did the SIR discuss
the potential effect of grazing on nesting habitat.

   The Forest Service’s efforts to minimize the importance of
the potential nesting habitat further emphasizes the shortcom-
ings of the Environmental Assessment. The Forest Service
suggests that the 1900 acres identified by Connelly as poten-
tial breeding habitat is less reliable because Connelly “made
this identification on the basis of the quality of the vegetation,
not on any documented breeding in this area.” However, this
argument undermines the Forest Service’s overarching posi-
tion that reliance on habitat alone is sufficient to predict sage
grouse viability. Moreover, it highlights the fact that the new
information regarding potential nesting habitat directly con-
tradicts the Environmental Assessment, which concluded
without explanation that nesting habitat is unavailable
because of the nature of the vegetation (and not as a result of
grazing).

   Ultimately, the Forest Service attempts to avoid preparing
a supplemental environmental assessment by suggesting that
weather presents an immediate bar to the use of the identified
habitat for nesting. However, the scientists who identified this
habitat considered weather patterns. For example, Connelly
noted that late brood-rearing habitats “are generally used from
July to early September but vary annually due to annual
weather conditions.” And Glenn Hockett, the NEC expert,
specifically rejected the premise that weather conditions fore-
close the use of the nesting habitat. In his declaration, he
noted:

    Although the Antelope Basin/Elk Lake area does
    receive a lot of snow in the winter, it melts in the
    spring. The importance of ephemeral (temporary),
    water sources from melting snow banks may play an
3728         NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
      important role in the sage grouse habitat suitability
      for nesting and early brood rearing on the project
      area.

Hockett Decl., December 24, 2003, p. 6. Thus, the Forest Ser-
vice’s conclusory assertion in the DN/FONSI that nesting is
impossible because of weather conditions is undermined by
the scientists’ observations.

   Given the presence of potential nesting habitat and the cor-
ollary effect on that habitat of cattle grazing, the 2004 infor-
mation impacted the project sufficiently that the
environmental assessment should have been further revised.
See Klamath 

. We note that a revised
environmental assessment considering the issues addressed
above might come to a different conclusion than the original
environmental assessment and necessitate the preparation of
an environmental impact statement.

IV.    CONCLUSION

   [12] Because the methodology utilized by the Forest Ser-
vice violated both the NFMA and NEPA, we reverse the dis-
trict court’s grant of summary judgment in favor of
Defendants, and remand this case for the agency to prepare a
new or supplemental environmental assessment consistent
with this opinion.

  REVERSED AND REMANDED.



KOZINSKI, Chief Judge, dissenting:

   The majority oversteps the limited role of a court reviewing
an agency’s decision. First, it holds that the Forest Service’s
216-page Environmental Assessment, six sage-grouse project-
area surveys, and bevy of supplemental reports all amount to
            NATIVE ECOSYSTEMS COUNCIL v. TIDWELL            3729
a “ ‘clear error of judgment’ that would render its action ‘arbi-
trary and capricious’ ” under the National Forest Management
Act. The Lands Council v. McNair, 

, 993 (9th
Cir. 2008). Second, on the basis of these same substantive
criticisms, the majority holds that the Service’s analysis was
too flawed to satisfy the National Environmental Protection
Act’s “hard look” requirement. See, e.g., Native Ecosystems
Council v. U.S. Forest Serv., 

, 1239 (9th Cir.
2005) (“Determining whether the Forest Service took the req-
uisite ‘hard look’ is judged against the APA’s arbitrary and
capricious standard.”).

  But ours is only the modest task of ensuring the Service
didn’t perform an arbitrary and capricious analysis or come to
an arbitrary or capricious conclusion. The Service did neither
so the majority is wrong to overturn its decision.

                               I

   The National Forest Management Act requires the Forest
Service to develop a general resource management plan for
every forest in the National Forest System. 16 U.S.C. § 1604.
Forest Plans permit productive uses of forests (such as graz-
ing) while preserving the habitat to support viable populations
of all pre-existing plant and animal life. Id.; 36 C.F.R.
§ 219.19 (2000). To keep track of animal populations, the
Forest Service designates a small number of “management
indicator species” to monitor as proxies for all the forest’s
animals. 36 C.F.R. § 219.19(a)(1). And, rather than go out
and individually count every animal, the Service often moni-
tors indicator species’ habitat as a proxy for their population.
We’ve long endorsed this proxy-on-proxy approach. See, e.g.,
Inland Empire Public Lands Council v. U.S. Forest Serv., 

, 761 (9th Cir. 1996).

   Forest Plans, by definition, cover entire forests.
Beaverhead-Deerlodge National Forest is the largest national
forest in Montana and, at 3.36 million acres, it is roughly the
3730        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
size of Connecticut. In the Beaverhead-Deerlodge National
Forest Plan, sage grouse are the indicator species for sage-
brush dependent animals forest-wide. The Antelope Basin/Elk
Lake project site, at 48,000 acres (1.4% of the total forest), is
just a bit larger than the District of Columbia. The Service
analyzed the project’s potential effects on the Forest Plan as
NFMA required and, as the Forest Plan required, it used sage
grouse as the indicator species for sagebrush-dependent ani-
mals.

   But that isn’t good enough for the majority, which holds
that it was arbitrary and capricious for the Service to rely on
sage grouse because grouse are “virtually non-existent in the
project area.” Maj. at 3718. When grouse are “absent from the
project area . . . the Forest Service cannot reasonably argue
that the proxy-on-proxy approach allows it to avoid separately
monitoring sage grouse population trends.” 

This
rule—that a project analysis is arbitrary and capricious unless
there is proof that each indicator species lives in the project
area—is entirely new. It has at least four problems.

   First, the majority doesn’t apply its new requirement fairly
to the record. The record does not show, and the Service does
not concede, that there are no sage grouse in the Antelope
Basin/Elk Lake project site. The record shows only that no
sage grouse “have been observed in the project area in the
past 15 years and sage grouse surveys in 2001-2003 did not
find sage grouse or their sign.” On the other hand, there is a
report of two sage grouse being taken illegally from the proj-
ect area in 2002. Rather than meaning that few sage grouse
live in the project area, this could just mean the sage grouse
in the project area are difficult to find. We’ve repeatedly
approved habitat monitoring when the indicator species is dif-
ficult to detect. See, e.g., 

. The major-
ity notes that “the government does not cite any ‘monitoring
difficulties’ that prevent detection of the sage grouse.” Maj.
at 3719 n.9. But why would it have? Courts have never
required that showing before. We can hardly fault the Service
            NATIVE ECOSYSTEMS COUNCIL v. TIDWELL            3731
for not providing an unnecessary justification in defense of a
well-established method. Creating new requirements and
applying them retroactively is the kind of “gotcha” jurispru-
dence we may not engage in.

   Second, the majority’s rule conflicts with our cases approv-
ing proxy-on-proxy analysis without requiring the indicator
species to be present in the project area. For example, in
Native Ecosystems Council v. United States Forest Service,
plaintiffs challenged the Service’s performing proxy-on-proxy
analysis without showing a viable population of the indicator

. We sided with the Service, explain-
ing that “[o]ur case law permits the Forest Service to meet the
wildlife species viability requirements by preserving habitat,”
provided that the habitat is monitored using reliable methods.
Id.; see also 36 C.F.R. § 219.19 (“[H]abitat shall be managed
to maintain viable populations . . . .” ). This is plainly incon-
sistent with the majority’s requirement that the Service prove
that each indicator species lives in the project area. Indeed,
requiring the Service to prove that each indicator species lives
in the project area effectively requires it to directly monitor
each animal’s population—precisely the cumbersome task
that proxy-on-proxy is meant to avoid.

   Third, the majority’s new rule will make it much harder for
the Service to plan on a forest-wide scale, rely on forest-wide
indicator species and administer general Forest Plans. When-
ever one of the Forest Plan’s indicator species is absent or
impossible to detect, the Service will have to make an ad hoc
exception. Today’s majority requires a stand-in indicator spe-
cies for a project area that is 1.4% of the total forest. Tomor-
row’s might do so for 0.14%. Pretty soon, before the Service
can allow grazing in the head ranger’s backyard it’ll have to
prove no adverse impact on the gophers. This flies in the face
of NFMA. See, e.g., 16 U.S.C. § 1604(f)(1) (The Forest Ser-
vice shall “form one integrated plan for each unit of the
National Forest System.”) (emphasis added); Idaho Sporting
Cong., Inc. v. Rittenhouse, 

, 962 (9th Cir. 2002)
3732         NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
(“[T]he Forest Service must conduct an analysis of each ‘site
specific’ action, such as a timber sale, to ensure that the action
is consistent with the forest plan.”).

   The majority argues that “[i]f the Forest Service decided to
select a project site consisting of the head ranger’s back-
yard . . . it must indeed analyze that particular site to deter-
mine the effects of the proposed action.” Maj. at 3720-21.
Nobody disputes that. See p. 

. It’s at the next
step of the analysis where we differ: the majority’s require-
ment that the Service come up with all-new indicator species
if it can’t prove that the species listed in the Forest Plan live
in the project site. The entire point of a forest-wide plan is
that complying with its forest-wide standards will ensure
forest-wide species and habitat preservation. Although the
Service must ensure that grazing in the backyard doesn’t hurt
any sage grouse habitat, it’s not required to demonstrate that
sage grouse actually live in the yard.

   Fourth, it’s not clear that an indicator species’ absence from
a particular project area undermines the Service’s habitat
analysis. NFMA’s goal is preservation of animal life across
the forest, which is necessarily determined using the Forest
Plan and the Forest Plan’s indicator species. See, e.g., Inland
Empire Pub. Lands Council v. U. S. Forest Serv., 

, 757 (9th Cir. 1996) (“[S]ite-specific projects must be
consistent with the stage-one, forest-wide plan.”). If sage
grouse are a proxy for all the animals that rely on sagebrush,
and the Service can show that it’s reliably maintaining sage-
brush at the levels required for sage grouse, then NFMA has
been satisfied. The absence of grouse in a particular part of
the forest may make it harder to double-check these methods,
but in this case nobody disputes the reliability of Connelly’s
Guidelines, which are part of the administrative record. John
W. Connelly, et al., Guidelines to Manage Sage Grouse Pop-
ulations and Their Habitats, 28 Wildlife Society Bulletin 967
(2000).
            NATIVE ECOSYSTEMS COUNCIL v. TIDWELL            3733
   The majority also criticizes more specific aspects of the
Service’s scientific analysis. But bare disagreement doesn’t
make the Service’s analysis arbitrary and capricious. See
Marsh v. Or. Natural Res. Council, 

, 378 (1989)
(“When specialists express conflicting views, an agency must
have discretion to rely on the reasonable opinions of its own
qualified experts even if, as an original matter, a court might
find contrary views more persuasive.”). This is especially true
where, as here, the court bases its objections on the findings
of a scientist who has actually endorsed the project being
reviewed. The majority’s central criticism is that “the very
guidelines used by the Forest Service militate against the For-
est Service’s assertion” that sage grouse can be monitored by
monitoring sagebrush. Maj. at 3721. The majority bases this
assertion almost entirely on supposed inconsistencies between
the Service’s analysis and the work of Dr. Connelly (the
Guidelines’ author). E.g., 

his co-authors
recognized that ‘populations of sage-grouse have been extir-
pated at places throughout their former range concomitant
with habitat loss and degradation, so that the species’ current
distribution is less closely aligned with that of sagebrush.’ ”).

   But Dr. Connelly published a lengthy review of the Ser-
vice’s project analysis (also in the administrative record)
explaining that “[t]he actions authorized by the Antelope
Basin/Elk Lake Environment Assessment are generally con-
sistent with the current sage-grouse management guidelines.”
John W. Connelly, A Review of USFS Management Activities
and Their Relationship to Sage-Grouse in the Antelope Basin/
Elk Lake Area of Southwestern Montana (September 15,
2004) at 14 (hereinafter Connelly Review). Connelly found
that “[t]he conclusions in the Anteleope Basin/Elk Lake Allot-
ment Management Plan EA . . . are reasonable and supported
by the available evidence. Effects to sage grouse resulting
from project implementation will likely be minimal. . . . The
actions authorized . . . appear [to] take a pro-active approach
to managing for potential sage grouse habitat.” 

3734        NATIVE ECOSYSTEMS COUNCIL v. TIDWELL
Courts are ill-equipped to second guess scientists, particularly
scientists who are interpreting their own scientific evidence.

                               II

   As the majority acknowledges, NEPA imposes no substan-
tive requirements but merely “exists to ensure a process.”
Maj. at 3725 (quotation omitted). Nonetheless, the majority
concludes that the Service’s use of the Forest Plan’s manage-
ment indicator species to evaluate the Antelope Basin/Elk
Lake Allotment Management Plan did not constitute “the req-
uisite ‘hard look’ mandated by NEPA.” Maj. at 3726. This
NEPA holding doubles down on the same point the majority
makes about NFMA—that no project can be undertaken with-
out studying animals that actually live in the project site. But
the majority never explains why violating NFMA’s substan-
tive requirements is necessarily enough to fail the more
lenient NEPA requirement of a “hard look” that doesn’t “rely
on incorrect assumptions or data.” Native Ecosystems Council
v. U. S. Forest Serv., 

, 964 (9th Cir. 2005). Even
if NFMA limited the Service to indicator species that live in
the project area (it doesn’t), a species’ absence doesn’t neces-
sarily make the Service’s extensive analysis of the project
area totally unreliable.

   The majority also criticizes the Service for not supplement-
ing its Environmental Assessment in the wake of the Connelly
Review. But this criticism is hollow on two levels. First, it
ignores the fact that the Connelly Review endorsed the Ser-
vice’s position. See pp. 

. Why (and how) would
the Service “respond” to an unqualified endorsement? Take a
bow? Second, the majority’s premise—that the Service never
addressed the Review’s finding that some of the project area
was suitable for nesting, maj. at 3726-27—is factually inaccu-
rate. The Supplemental Information Report explains on page
five that “[c]attle do not enter the Elk Lake Allotment, where
1,900 acres of possible nesting habitat was identified, until
June 26 or later.” (emphasis added). It reiterates the point on
            NATIVE ECOSYSTEMS COUNCIL v. TIDWELL           3735
page twelve: “likelihood of disturbance by livestock to nest-
ing sage grouse appears to be minimal as normally the range
is not ready for livestock grazing until after the peak of sage-
grouse egg incubation.” The Service clearly considered the
Review’s finding. It’s just that the Service—like the Review’s
author—concluded that the project was consistent with these
findings. A hard look is a hard look no matter what the Ser-
vice sees, even if judges see something else.

                           *   *   *

   The majority acts as both legislature and biologist. It acts
as legislature by inventing new NFMA requirements and as
biologist by dissecting reports about sage grouse in a mis-
guided effort at second-guessing those reports’ authoring sci-
entists. We should abstain from this sort of law office science.
The Service has already printed hundreds of pages analyzing
the Antelope Basin/Elk Lake’s suitability for summer grazing.
Both NFMA and NEPA were satisfied. We have no authority
to stand in the way.