FOR PUBLICATION



### UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT

B E S S B AI R ; T R

I S HA L E E L O TU S ; J E F F R EY H E D I N ; D A V I D S P R E E N ; C E N T E R F O R B I O L O GI C AL D I VE R S I TY ; E N

VI RONME

N TAL P RO T E C T I ON I NF O R

M A T I ON C E

N T E R ; C AL I F O R

N I A N S F O R A L T E R

N A T I VE S T O T O XI C S ; F R

I E ND S O F D E L N O R

T E , Plaintiffs-Appellees ,

v

. C AL I F O R

N I A D E P AR

T ME N T O F T R A N S P O R TAT I ON ; T O K S O MI S HAK

I N , in his capacity as Director of the California Departm ent of Transportation,

Defendants-Appellants. No. 19-16478

D.C. No. 3:17-cv-06419- W HA

OPINION

Appeal from

the United States District Court for the Northern District of California W illiamAlsup, District Judge, Presiding Argued and Subm itted October 13, 2020 San Francisco, California

Filed Decem

ber 2, 2020B AI R V

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B efore: Ferdinand F. Fernandez, Kim McLane W ardlaw,

and Daniel P. Collins, Circuit Judges. Opinion by Judge Fernandez; C oncurrence by Judge W ardlaw

SUMMARY *

Environmental Law Reversing the distric t court’s judgm ent in favor o f plaintiffs, v acating an injunction, and rem anding, th e panel held that th e California D epartm ent of Transportation
com plied with the National En vironm ental Policy Act in relying on an Environm ental A ssessm ent for a pro p o sed h ig hw ay im

provem ent project within Richardson Gro v e S tate Park. Granting partial summ ary judgm ent in favor of plaintiffs, the district court concluded tha t Ca ltrans had failed adequately to consider certain i ssues and therefore had not taken the requisite “hard look” at the environm ental im pacts of the Project, and the 2010 Environm ental Assessm ent (EA),
as supplem ented and revised, was in a dequate. The district court concluded that substantial questions had been raised as to the effects o f the Project, and it o rdered Caltrans to prepare an environm ental im

pact statem ent (EIS). The district court enjoined Caltrans f

rom proceeding with the Project until the EIS was finalized.

* This summ ary constitutes no part of the opinion of the court. It h as been prepared by court staff for the convenience of the reader.B AI R V

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Rev e r s i n g , the panel held that Caltrans based its 2017 finding of no significant im pact (FONSI) upon the analysis contained in the revised EA, which incorporated the analysis of th e 2 0 1 0 EA and the 2013 R evised Supplem ental E A

. Because Caltrans’ 2010 EA, as supplem ented and revise d , constituted the “hard look” at the Project’s effects required by NEPA, Caltrans’ issuance of the 2017 FONSI was reasonable. The panel held that none of the pur po rted inadequacies identified by the district c o urt rendered the revised EA arbitrary or capricious. Concurring, Judge W ardlaw wrote th at she concurred in the m ajority opinion, a n d Ca l trans did not violate N EPA because its rel i a nce on the EA w as not arbitrary and capricious. Judge W ardlaw wrote separately to em phas i z e that: (1) the adm inistrative record was p a i n ful to review; (2) if significant new inform ation i s d i s c overed during the proposed constru c tion o r substantial project changes are m ade, Caltrans m ay need to reevaluate its analysis; and (3) the Project seem s likely to provide new data on the effects of construction on old-growth redwoods, which could prove im portant to future decisions surrounding these h istoric trees.

C OUNSEL Stacy Jayne Lau (argued), Michael A.G. Einhorn, and Angela Wuerth; L ucille Y. Baca, Assistant Ch ief Counsel; G. Michael Harrington, Deputy Chief Counsel; Eri n E. Holbrook, C hief Counsel; State of California Departm ent o f Tr ansportation – Legal Division, Oakland, California; for Defendants-Appellants.B AI R V

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Stu a rt G. Gross (Argued) and Tim othy S. Kline, Gross & Klein LLP, San F rancisco, California; T odd R. Gregorian and Garner F. Kropp, Fenwick & W est LLP, Sa n Francisco, California; for Plaintiffs-Appellees.

OPINION FERNANDEZ, Circuit Judge:

Th i s environm ental appeal arises from a highway im provem ent project proposed by the California Departm ent of Transportation (collectively w ith i t s director, Toks Om ishakin, Caltrans). Plaintiffs Bess Bair, Trisha Lee Lotus, Jeffrey H edin, David Spreen, the Center for Biologic al Diversity, the Environm ental P rotection Inform ation Center, Californians f

or Alternatives to T o xics, and Friend s of del Norte (collectively, Bair 1 ) challenged the project on a variety of grounds, including the f ailure to com

ply with the N ational Environm ental Policy Act of 1969, Pub. L. No

. 91–190, 83 Stat. 852 (1970) (NEPA). The district court determ ined that Caltrans arbitrarily and cap r i c iously relied upon the 2010 Environm ental Assessm ent (2010 EA), as supplem ented and revised, because, it held, that docum ent failed to sufficiently consider certain “significant issues.” Bair v. Cal. State Dep’t of Transp. , 385 F. Supp. 3d 878, 886 (N.D. Cal. 2019). The district court also enjoined Caltrans from contin u ing the project until it finalized an appropriate environm ental im pact statem ent (EIS). It then entered a final judgm ent against Caltrans. W e reverse and rem and.

1 W hile the plaintiffs other than Bair have changed from tim e to tim e during the m ore than ten years of litigation th a t h as e nsued, unless otherwise noted, the plaintiffs will hereafter be referred to as Bair.B AI R V

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I. BACKGROUND

Richardson Grove State Park (the Grove) com prises approxim ately 2,000 acres within the redwoo d forests o f southern Hum

boldt County, California, and is bise cted by United States Highway 101. W ithin the Grove, Highway 101 is a two-lane high way “on a n onstandard alignm ent” with tight curves and narrow travel lanes and roadway shoulders. A num ber of trees, including old-growth redwood trees, 2 abut the roadway as it m eanders through th e Gr o v e

. In light o f antiquated roadway design, there are restrictions on the types of vehicles that m ay travel that portion of the h ighway. Sixty-five foot long “California Legal” trucks are perm itted, but industry-standard S urface T ransportation Assistance A ct of 1982 3 (STAA) trucks generally are not. STAA trucks are longer than California L egal trucks and can carry larger cargo volum es, although both classes of tru c k s are subject to the
sam e weight lim itation. Because of their longer length, STAA tr u cks navigating the highway’s tight curves frequently “off-track” into the o p p o s ing traffic lane or onto the roadway shoulder.

Th e STAA truck restriction at the Grove is the o n l y rem aining im

pedim ent to STAA trucks traveling into Hu mboldt County via H ighway 101. Caltrans has l o n g sought to rem ove that roadblock, but abandoned p revious efforts b ecause of the substantial p r o j e cted expense, am ong other things. In 2007, Caltrans learned that the existing roadway co u ld b e strateg ically widened to render it accessible

2 Caltrans defined “old growth redwood[s]” as “trees over 30 inches in diam eter at breast height (4.5 feet above ground level).”

3 Pub. L. No. 97–424, 96 Stat. 2097 (1983).B AI R V

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to STAA trucks, and Caltrans developed the Richa rdson Grove Operational Im

provem ent Project (th e Project) to do just that. The Project involves slightly widening the roadway and straightening som e curves in certain locations along a one-m ile stretch of H ighway 101, largely within the Grove. Its purposes are to accomm odate S TAA truck travel, im prove the s a fe ty and operation o f Highway 101, and im p rove the
m ovem ent of goods into H um boldt County. The speed lim it would rem ain unchanged at thirty f ive m iles per hour. Caltrans assum ed responsibility for obtaining environm ental approval for the Project pursuant to NEPA. See 23 U.S.C. § 327(a)(2)(A), (B)(i).

A. The Project as originally proposed in 2010 The original 2010 EA included extensive analysis of the Project’s environm ental effects and efforts to m inim ize those effects (developed in consultation with the California Departm ent of Parks a n d Recreation (State Parks)). More than 100 pages of the 2010 EA were dev ot e d to analyzing various environm ental im pacts, such as the effects on the nearby South Fork Eel Ri ver, the Grove and its recreation facilities, econom ic growth, traffic, water quality, noise, local plant and anim al species (pa rticularly old-growth redwood trees), and protected or threatened species.

Caltrans u ltim ately determ ined that the im p a c t s to the Grove would be m inor, and would prim arily consist of “tree
rem oval resulting from c u ts and fills that are necessary to
accomm odate the highway im provem ents,” a s we ll as theB AI R V

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effect on trees wh o s e structural root zones 4 were w ithin the construction area. Although som e trees wo u l d be rem o ved,
none o f those would b e old-growt h r edwoods. And while construction would occur in the structural root zones of fewer than 80 old-growth redwoods, plans were m ade to m itigate its effects. For exam

ple, Caltrans proposed to increase the height of the roadbed where p ossible t o avoid severing tree roots, use a thinner roadbed m aterial to allow g r e a ter perm eability, conduct som e construction (excavation) by hand, water trees during the summ er, and rem ove som e invasive plants. In light of those m easures, both the Caltrans arborist (Darin Sullivan) and the arborist h i r e d by Save the Redwoods League (Dennis Yniguez) determ ined th at the Project as proposed in 2010 “would not significantly im pact the root health of the old growth trees adjacent to the
con s truction.” C altrans issued the EA and Finding of No Significant Impact (FONSI) for the Project in May 2010.

B. Past litigation

Bair filed suit regard in g th e Project in both 2 010 5 and 201 4, 6 e ach tim e m aking sim ilar claim s. In the First Litigation, the district court granted partial summ ary judgm ent to the plaintiffs and ordered Caltrans to undertake

4 As defined in the 2010 EA, “the structural root zone i s a circular
area with the tree trunk at the center with a radius equal to t hree t im es the diam eter of the tree trunk m e a s ured at 4.5 feet above ground level,” and “is where m ost of the [tree’s] nutrient and water absorption occurs.”

5 Bair v. Cal. Dep’t o

f Transp. , No. 3:10-cv-04360-W HA (N.D. Cal. 2010) (the First Litigation).

6 Bair v. Cal. Dep’t o

f Transp. , No. 3:14-cv-03422-W HA (N.D. Cal. 2014) (the Second Litigation).B AI R V

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additional stu dies, such as preparing n ew m aps of each oldgrowth redwoo d tree, its root health zone, and the environm ental im

pacts to each tree. Bair , 385 F. Supp. 3d at 883. Caltrans then revised its analysis accordingly. After
comm issioning a tree report from arborist Yniguez, it issued
a 2013 Supplem ent to the 2010 EA. Caltrans then took public
comm ents, responded to them , and finally issued a N EPA R evalidation fo r th e Project in January 2014. It found that the 2010 EA and FONSI rem ained valid.

In the Second Litigation, B air challenged the re-validated Project on m any o f th e sam e grounds as in the First Litigation. See id. The Second Litigation was dism issed after Caltrans withdrew the FONSI 7 in light of an adverse ruling in
a parallel proceeding in the California C ourt of Appeal. See Bair , 385 F. S upp. 3d at 8 83–84; Lotus v. De p’t of Transp. , 167 Cal. Rptr. 3d 382, 393 (Ct. App. 2 014). In response to the California court’s order, Ca l trans slightly reduced the scope of the Project, and Yn iguez prepared another tree report.

C. 2017 Project proposal and current litigation

Since the original issu a n c e o f the E A in 2010, Caltrans has m odified the Project to reduce its im pact, p r i m arily by narrowi n g the proposed roadbed (roadway shoulders). The Project now requires the rem oval of 38 trees, none of which
are old-growth redwoods, and construction will occur within the structural root zones of 78 old-gr owth redwood trees, 72 of which are within the Grove. T hat construction activity largely consists o f (1) excavation to a m aximum depth of two

7 Notice of Rescission of Finding o f N o Significant Im pact, 79 Fed. Reg. 70,612-01, 70,612 (Nov. 26, 2014).B AI R V

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. 9 feet; (2) covering som e of the root zone with im p ervious surface (roadbed); and (3) placing fill over tree roots. A s noted, Caltrans retained arborist Yniguez t o evaluate the effects of the Project on the redwoods and to p ro duce two reports summ arizing his c o nclusions. In general, he determ ined that the Project “would not have any substantial detrim ental effect on individual old-growth redwoods

. . . o r the overall health of the stand of redwoods in Richar d s o n Grove.” His repo rt s were b ased on scientific literature regarding redwoods, his three decades of experience as an arborist, m

ultiple site v isit s to the Grove (including a helicopter flight to evaluate tree crowns), and m aterials provided by Caltrans su ch as the EA, detailed schem atic drawings of all trees with root zones within the Project area, and individua l tree details for each. Yniguez assessed each tree individually to determ ine the likely effect on its he a lth from the root zone disturbances created by the Projec t , b o th with and w ithout m itigation m easures, and assigned each tree
a rating corresponding to the anticipated effects on its h ealth, ranging from Level 0 to Level 6. He c oncluded that the Project w ould not jeopardize the lives of any o ld-growth redwood trees, and that the vast m ajority of such trees would
s u stain no decline in foliage density or health as a r e s u l t of the Project. In the absence of m itigation m easures, Yniguez decided that ap proxim ately eighteen old-growth redwood trees m ay m anifest “a short-term visible reduction in foliage density that is still well within the adaptive capabilities of the tr e e” (Level 4 rating), while one such tree m ay undergo “a reduction in root health sufficient to cause lasting vi s i b le dieback of wood in the upperm ost crown, although tree health and surviva l [would] not [be] threatened” (Level 5 rating). Including the Project’s m itigation m easures substantially reduced those effects: Yniguez determ ined that only three old-growth redwood trees would rem ain in L evel 4 and noneB AI R V

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in L evel 5 if the proposed m itigatio n m e a s ures were im plem ented. Yniguez thus conc l u d e d that “[n]one of the proposed highway alterations is of sufficient m agni tu de to th r eaten the health or stability of any old-growth redwo o d ” because “disturbances w ould be confined to a sm all percentage of the area o ccupied by roots and w ould b e well within the adaptive capabilities o f th e tree[s].” Moreover,
even withou t m itigation m easures, Yniguez concluded that “the lim ited root disturbance would b e inconsequential to the appearance, stability, and continued health of the o ld-growth redwoods in Richardson Grove.”

Caltrans largely agreed with Yniguez’s analysis, but also considered other evidence, such as scientific literature about the resilience, health, and d evelopm ent of redwoods and their
roo t s y s tem s generally, the condition of the particular oldgrowth redwood trees in th e Project area, and the specific activities and m itigation m easures com prising the Project. Caltrans thus concluded that “[i]n no case would root disturbance h ave a significant detrim ental effect on the health
or stability o f old-growth redwoods.” In May 2017, Caltrans issued revisions to the EA and a new FONSI.

Bair filed this litigation in 2017, 8 again raising c l a im s sim ilar to those that had b een m ade in the First Litigation and the Se co n d Litigation, specifically: seven claim s alleging various violations of NEPA, as well as claim s for a violation of section 4(f) of the Departm ent of Trans p ortation Act, 9 a

8 Bair v. Cal. Dep’t o

f Transp. , No. 3:17-cv-06419-W HA (N.D. Cal. 2017).

9 23 U.S.C. § 138(a); see also 23 C.F.R. § 774.1.B AI R V

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violation of section 7 of the W ild and Scenic Rivers Act, 1 0 a violation of the Adm inistrative Procedure Act (APA), 1 1 a declaration that Caltrans is responsible fo r Bair’s attorney’s fees and costs, 1 2 a n d i njunctive relief. 1 3 The district court g ra nted Bair partial summ ary judgm ent as to som e of th e NEPA claim s. Bair , 3 85 F. Supp. 3d at 898. 1 4 Th e d i strict court identified certain issues th a t , i n its view, Caltrans h ad not adequately considered: whether (1) redwoods would suffoca te when m ore than half of their root zones were covered by p avem ent; 1 5 ( 2 ) construction in a redwood’s structural root zone wo u ld cause root disease; 1 6 (3) traffic noise would increase because of the larger size of the S TAA trucks or because of additional nu m bers of trucks; 1 7 and (4) redwoods would suffer m o re frequent and severe dam age as a result o f strikes by S TAA trucks. 1 8 Because of those deficiencies, the district court determ ined that Caltrans h ad not taken the requisite “hard look” at the environm ental im pacts o f the Project, and that the EA was i n ad e quate. Id.

10 16 U.S.C. § 1278(a).

11 5 U.S.C. § 706(2)(A), (D).

12 See 23 U.S.C. § 327(a)(2)(G); Cal. Civ. Proc. Code § 1021.5.

13 Fed. R. Civ. P. 65(a).

14 The district court did not address Bair’s other claim s. See id.

15 Id. at 886, 888.

16 Id. at 891.

17 Id. at 892–93, 895.

18 Id. at 895.B AI R V

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at 890–91, 895, 898. In light o f those supposed shortcom ings in the EA, the district court c o n c l u ded that substantial questions had been raised as to the effects of the Project, and it ordered Caltrans to prepare an EIS. The district court also enjoined Caltrans from proceeding with the Project until the EIS was finalized. Caltrans tim ely appealed. S ee Fed. R. App. P. 4(a)(1)(A).

II. JURISDICTION

The district court had jurisdiction pursuant to 28 U.S.C. § 1331. W e have jurisdiction. 28 U. S.C. § 1291; see HonoluluTraffic.com v. Fed. Transit Admin. , 742 F.3d 1222, 1229 (9t h Ci r

. 2014); Alsea Valley All. v. Dep’t of Com. , 358 F.3d 1181, 1184 (9th Cir. 2004).

III. STANDARDS OF REVIEW

“W e review de novo a d istrict court’s grant of summ ary judgm ent.” Am. Wild Horse Campaign v. Be rnhardt , 963 F.3d 1001, 1007 (9 th Cir. 2020). “[A]gency d ecisions that allegedly violate NEPA” are re vi e we d “under the Adm inistrative Procedure Act, and we set aside those decisions only if they are ‘arbitra ry , c apricious, an abuse o f discretion, or otherwise not in accordance with law.’” Id. ; see also 5 U.S.C. § 706 (2 ) ( A)

. “Whether a plaintiff has exhausted required adm inistrative r e m edies is a question o f law reviewed de novo.” Great Basin Mine Watch v. Hankins , 456 F.3d 955, 961 (9th Cir. 2006).

IV. DISCUSSION

NEPA generally “requires a f ederal agency

. . . to prepare ‘a detailed statem ent on

. . . the environm ental im p ac t ’ o fB AI R V

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‘m ajor Federal actions significantly affecting the qua l it y o f the hum an environm ent,’ ” 1 9 a d ocum ent known as an EIS. 2 0 However, the regulations alternatively “allow an ag e n c y to prepare a m ore lim ited docum ent, an En v ironm ental Assessm ent (EA), if the agency’s proposed action

. . . would [not] clearly require the p roduction of an EI S. ” De p ’t of Transp. v. Pub. Citizen , 541 U.S. 752, 757, 124 S. Ct. 2204, 2209–10, 159 L. Ed. 2d 60 (2004); see a l s o 4 0 C.F.R. § 1501.4(b)–(c). An EA is “a ‘concise p ublic docum ent’ that ‘[b]riefly provide[s] sufficient evid e n ce and analysis for determ ining whether to prepare an [EIS].’” Dep’t of Transp. , 5 41 U.S. at 757, 1 24 S. C t. at 2210; see also Ctr

. f o r Biological Diversity , 538 F .3d at 1185; 40 C.F.R. § 1508.9(a)–(b).

If the “agency determ ines that an E IS is not required

. . . , it

. . . issue[s] a ‘finding of no significant im p act’ (FONSI), which briefly p resents the reasons why the proposed agency action w ill not h ave a significant im pa c t o n the hum an environm ent.” Dep’t of Transp. , 541 U .S. at 757–58, 124 S. Ct. at 2210; see also 40 C.F.R. §§ 1501.4(e), 1508.13. That decision “can be set aside only upon a showing that it was

19 Ctr

. for Biological Diversity v. Nat’l Highway Traffic Safety Admin. , 538 F.3d 1172, 1 185 (9th Cir. 2008); see also 42 U.S.C. § 4332(C).

20 See 40 C.F.R. § 1 501.4(a), (c). The Council o n En v i ro nm ental Quality has adopted new regulations that becam e effective on Septem ber 1 4, 2020. Update to the Regulations I m plem enting the Proc e dura l Provisions of the National E nvironm ental Policy A ct, 85 Fed. Reg. 43,3 0 4, 4 3 ,304 (July 16, 2020); see also 40 C.F.R. § 1506.13 (2020). Because Caltrans applied t he previous regulations to the Project, so do we. Unless otherwise indicated, the regulations ci t e d h erein are the versions in effect when the district court rendered its decision.B AI R V

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. 14 ‘arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.’” Dep’t of T ransp. , 541 U.S. at 763, 124 S

. C t. at 2213; see also 5 U.S.C. § 706(2)(A); O cean Advocs. v. U.S. Army Corps of Eng’rs , 402 F.3d 846, 858 (9th Cir. 2005). Determ ining whether the agency’s decision not to prepare an EIS was arbitrary and capricious “requires u s to determ ine whether the agency has taken a hard look at the consequences of its actions, based [its decisio n ] o n a consideration of the relevant fac t o r s , and provided a convincing statem ent of reasons to ex p l a i n why a project’s im pacts are insignificant. ” N a tive Ecosystems Council v. U .S. Forest Serv. (

Native Ecosystems I

), 4 28 F .3d 1233, 1239 (9th Cir. 2005) (internal quotation m arks o m itted). A lthough our review “is ‘searching and careful , ’” i t is nevertheless narrowly c ir cum scribed, “and we cannot substitute o ur o wn judgm ent for that of the [agency].” Ocean Advocs. , 402 F.3d at 858. Instead, “[w]e ask ‘whether the [agency’s] decision
was based on a c o n si d e ration of the relevant factors and whether there has been a c lear error o f judgm ent.’” Id. at 859; see also In Def. of

Animals v. U.S. Dep’t of the Interior , 751 F.3d 1054, 1072 (9 th Cir. 2 014). But we m ust keep in
m ind that we ar e not “a panel of scientists that instructs the [agency] h ow to validate its hy potheses

. . . , chooses am ong scientific studies

. . . , [or] orders the agency to explain every possible scientific uncertainty.” Lands Counci l v

. McNair , 537 F.3d 981, 988 (9th Cir. 2008) (en banc), overruled in part
on o ther grounds b

y Winter v. Nat. Res. Def. Council, Inc. , 555 U.S. 7, 21–22, 129 S. Ct. 365, 37 5 , 1 7 2 L. Ed. 2d 249 (2008).

Caltrans based its 2017 F ONSI upon the analysis contained in the revised EA, which incorporated the analysis of the 2010 E A an d th e 2 013 R evised Supplem ental E A

. Because Caltr a n s’ 2 010 EA, as supplem ented and revised,B AI R V

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constituted the “hard look” at the P roject’s effects required by NEPA, Caltrans’ issuance of the 2017 FONSI was reasonable. T h e d istrict court erred in gr a n t i ng p artial
summ ary judgm ent to Bair. A s w e explain in the ensuing paragraphs, none of the purported inadequacies it ide n t i fi ed rendered the revised EA arbitrary or capricious.

First , as to redwood tree suffocation, Caltrans sufficiently considered the effect o f paving over po rt i o n s of tree root
zones. The Project wil l use a special m aterial to allow “‘greater porosity’” and to “‘prom ote air circulation’” under the asphalt, 2 1 and Ca lt r ans considered the aggregate am ount
o f new roadbed m aterial that would be placed over th e structural root zones. Yniguez specifically relied in part upon Ca l trans’ selection of perm eable m aterial, the m inor a n d lim ited areas of new asphalt, and Caltrans’ decision to narrow the proposed r oadway shoulders where possible in reaching his conclusion that the Project would not create extrem e stress in the redwoods or overwhelm their natural resilience. 2 2 And, as m ore particularly described in Pa rt I.C of this Opinion, Yniguez and Caltrans thoroug h ly assessed the
am ount of paving that would be placed over the root zone o f
e a ch tree. Caltrans considered the possibility that paving could h arm the trees, but sim ply (and reasonably) concluded that there was sufficient evidence to the contrary. See In Def.

21 Bair , 385 F. Supp. 3d at 888.

22 Caltrans reasonably r elied u pon Yniguez’s re po rts, and Bair does not argue otherwise. See Native Ecosystems Council v. Weldon ( Native Ecosystems II

), 6 97 F.3d 1043 , 1 051–52 (9th Cir. 2 012). Caltrans’ reliance on e v i dence specifically p ertaining to redwoods (including Yniguez’s reports) was em inently reasonable, especially because the record reflects that redwood trees and t heir root system s a re p a rt icularly (uniquely) resilient.B AI R V

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. 16 of Animals , 751 F.3d at 10 7 2 ; Lands Council , 537 F.3d at 1003. That was not arbitrary or capricious. See In Def. of Animals , 751 F.3d at 1072–73. 2 3 The di s tr i c t c ourt erred in concluding that the EA failed to adequately c o n s ider the effects of paving over portions of the root zones of certain trees.
Second , as to construction within root zones, Ca ltrans appropriately considered the extent and effect of the construction activity that would o ccur in the stru c tura l root
zones of redwood trees, including construction guidelines in
a St a t e Parks handbook. The record plainly belies Bair’s contention that Caltrans failed t o c onsider the effects o f construction. On the contrary , a s d e s cribed in Part I of this Opinion, the record is replete with Caltrans’ com p rehensive analyses o f the extent and effects of construction acti v i ty in the root zones o f individual trees. See Cold Mountain v. Garber , 375 F.3d 884, 893–94 (9th Cir. 2004 ). 2 4 As to the

23 Moreover, there is no evidence supporting the district court ’s
assum ption th at 50% paving over root zones is som e sort of “ t hreshold” dem arcating a “‘danger zone’” or “ red zone” for redwood trees. Bair , 385 F. S u

pp. 3d at 8 88–89. Rather, that i s an unwarrante d inference drawn from a m isreading of evidence in t he record. Indeed, no comm ents
or evidence in the adm inistrative record raised the 5 0% t hreshold issue. That suggests that the issue was not even adm inistratively exhausted. See Barnes v. U.S. Dep’t of Transp. , 6 55 F.3d 1124, 1132, 1135–36 (9th Cir. 2011).

24 The district court erred in criticizing Caltrans for failing to consider
w h e ther root disease would arise from root injuries caused by construction. See Bair , 385 F. Supp. 3d at 891. Caltrans reasonably relied upon its expert’s o p i n ion that redwoods have “no im p ortant

. . . disease
enem ies”—evidence tailored to r edwoods specifically, rather than trees in general. See In Def. of

Animals , 751 F .3d at 1072; City of Carmel-By-TheSea v. U.S. Dep’t of Transp. , 123 F.3d 1142, 1151 (9th Cir. 1997).B AI R V

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sentence in State Parks’ h andbook that recomm ended that no construction should take place in the structural root zone “of
a protected tree,” it is not clear that it applied to the affected redwoods or influenced State Parks’ opinion of the Project, o r that Caltrans w as obligated to defer to o r adopt that opinion. See Wild Ea r th G uardians v. Provencio , 923 F.3d 655, 672 (9th C ir. 2019); s e e a lso Native Ecosystems I , 428 F.3d at 1242. NEPA anticipates that the adm inistrative record m ay contain contradictory and conflicting o p i n ions, expert and otherwise, 2 5 and d oe s n o t require an agency to follow all
recomm endations m ade by comm entators, other agencies, o r experts. 2 6 Thus, to the extent that the r e c o mme ndation in St a te Parks’ handbook is relevant here, Caltrans could (and did) reasonably refuse to follow it, especially when Caltrans relied upon evidence specifically pertaining to the effects o f construction o n redwoods in general and the redwoods in the Pr o j e ct a rea, in particular. In f ine, the district court erred wh e n it decided that Caltrans failed to sufficiently conside r the S tate Parks han dbo o k and the im pact of construction in the structural root zones of old-growth redwoods.

Third , as to traffic vol u me and noise, the district court erred when it decided that Caltrans failed to adequately consider how the v isitor exp e r ience to the Grove would be affecte d b y the presence of STAA trucks, particularly with regard to whether they w ould be m ore num erous or generate
m ore noise. Bair , 385 F. Supp. 3 d at 891–92, 895. Caltrans’ EA concluded that truck traffic would not increase as a result of the Project, and it properly relied upon record evidence to

2 5 City of Carmel-By-The-Sea , 123 F.3d at 1151; see also In D e f

. o f Animals , 751 F.3d at 1072.

26 See WildEarth Guardians , 923 F.3d at 672.B AI R V

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do so, including: a survey o f regional business owners, traffic studies in n earby areas suggesting little latent dem and for the route, the fact that highway capacity would be unchanged, and Caltrans’ opinion that STAA trucks currently using the strai g h t e r alignm ent and faster travel tim e of Interstate 5 to reach m ajor coastal cities were unlikely to detour through the Grove. See In Def. o

f Animals , 751 F. 3 d a t 1072. Caltrans reasonably concluded from that evidence th a t traffic would not increase as a result of the P roject. Thus, Caltran s’
c o n c lusion that traffic would not increase is entitled to deference. See WildEarth Guardians , 923 F.3d at 672; N a tive Ecosystems II

, 697 F.3d at 1052–53; cf. O cean Advocs. , 402 F.3d at 865–66 (agency failed to consider possible traffic increase). Moreover, in light o f its conclusion that tru c k traffic w ou ld n o t in crease, C altran s also reaso n ab ly co n clu d ed tha t traffic noise would not appreciably increase. Although the d istrict court stated that it believed STAA trucks would be noisier th an California L egal trucks because their tractor un its “are bigger and hea v ie r ,” 2 7 it cited n o evidence for its
assum ptions about the size and weight of STAA tractor units,
or its belie f about their noise in com parison to California Legal trucks. No r h ave we b een p ointed to any evidence o f that in the record. A district court has no m ore license to act
as “a panel o f scientists” than we have. Lands Cou ncil , 537 F.3d at 988. Caltrans adequately considered the Project’s effects on b oth traffic and traffic noise in the Grove, and reasonably co n cluded that the im pacts would not be significant.

Fourth , as to collisions with trees, the district court erred by determ ining that Caltrans should have a n a lyzed whether the Pr o ject could cause trees to: suffer m ore frequent

27 Bair , 385 F. Supp. 3d at 894–95.B AI R V

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collisions with trucks because STAA tru c k s a re longer and
m ore difficult to m aneuver; and sustain m ore dam age from collisions b ecause S T AA trucks are heavier and their engine
com partm ents m ore protruding than California L egal trucks. Bair , 385 F. Supp. 3 d at 895. Caltrans’ analys i s was not arbitrary and capricious. S ee Lands Council , 537 F.3d at 993. As to collision frequency, the undisputed purpose of the Project is to widen the road in order to provide room for offtracking STAA trucks, and Caltrans rea s onably concluded that doing so would d ec r e a s e the incidence of vehicles colliding w ith trees. Bair’s assum p tion that the collision risk will i nc r ease because the pavem ent will be closer to som e trees ignores that the pavem ent is m oving farther from other trees. 2 8 Caltrans’ c o nclusions regarding the frequency o f collisions were reasonable and enti t l e d to deference,
e s p ecially b ecause they pertain to an “area[] of agen c y expertise.” Nat’l Parks & Conservation Ass’n v. U .S. Dep’t of T ransp. , 2 22 F .3d 677, 682 (9th Cir. 2 000); see also Lands Council , 537 F.3d at 993.

As to dam age severity, we have not locate d any comm ents o r docum ents in the adm inistrative record which indicate that S TAA trucks w ould cause m or e d am age when they strike trees. Thu s , i t appears that issue was not adm inistratively exhausted. See Barnes , 655 F.3d at 1132, 1135–36. And even if the issue had been ex hau s t e d , the district court’s speculation that trees would suffer m ore severe dam age from collisions because of the weight or shape of STAA trucks is not supported by any evidence in the

28 It also ignores record evidence suggesting that the num b er of trucks traveling through the Grove m ay actually decrease b eca u s e s o m e of the California Legal t

rucks that would otherwise drive through the Grove m ay be replaced by fewer STAA trucks.B AI R V

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record. It was reasonable for Caltrans’ EA not to ant icipate that unfounded speculation. Se e L ands Council , 537 F.3d at 1002. W e reject Bair’s argum ent that because Caltrans was responsible for drafting the EA, it was also required to am ass e vidence dem onstrating the com parative dam age caused t o trees by collisions with STAA trucks and California Legal trucks. See 4 0 C.F.R. § 1508.9 ( a )

. While it is arbitrary and capricious for an agency to “‘entirely fail[] to consider an im portant aspect of the problem ,’” that did not occur here. Lands C o uncil , 537 F .3d at 9 93. As d e scribed above, Caltrans considered the effects of th e Pr oject with regard to traffic volum e, noise, ease of n avigation, and tree collisions. An agency is not required “to address in detail

. . . every single comm ent

. . . to prove that [it] ‘considered’ the relevant factors,” 2 9 much less to anticipate conclusory supposition about speculative and tangential effects that are not supported by evidence in the record. 3 0

For those reasons, we a re satisfied that Caltrans took a hard look at the consequences of the Project, and adequately considered the r e l e vant f actors. See Native Ecosystems I , 428 F.3d at 1239. That Bair or the district court m ay disagree with Caltrans’ conclusions “does not cons ti tute a N EPA violation.” Native Ecosystems II , 697 F.3d at 1053; see also WildEarth Guardians , 923 F.3d a t 672. Thus, the district court erred in finding Ca l trans’ EA arbitrary and capricious and in setting aside the 2017 FONSI.

29 In Def. of Animals , 751 F.3d at 1072.

30 See WildEarth Guardians , 9 23 F.3d at 672; Native Ecosystems II , 697 F.3d at 1053, 1055; see also Am

. Wi ld Ho r se Campaign , 963 F.3d at 1008–10.B AI R V

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In light of our conclusion, we reverse the district court’s judgm ent requiring Caltrans to produce an EIS and enjoining it from continuing the Project until it has done so. An agency m ust prepare an EIS “[i]f there is a substant i a l qu e stion whether an action ‘m ay have a significant effect’ o n the environm ent.” Ctr. f

o r Biological Diversity , 538 F.3d at 1185; see also 4 2 U.S.C. § 4332(C); 40 C.F.R. §§ 1502.1, 1508.18, 1508.27. The d istrict court’s rationale for requiring
an EIS was predicated on its erroneous conclusions about the Project’s effects on redwood tree health and possible increases in truck traffic and nois e

. Because w e have determ ined th a t th e EA’s analysis was adequate in those respects, the district court necessarily erred in setting aside the 2017 FONSI and o rdering Caltrans to prepare an EIS if it desired to proceed. See D ep’t of Transp. , 541 U.S. at 762–64, 124 S. Ct. at 2212–13. 3 1

V. CONCLUSION

The parties have engaged in contentious litigation over the (relatively lim ite d ) Pr oject for m ore than ten years. Howe v e r, Caltrans’ environm ental analyses regarding the redwoods and traffic satisfied NEPA’s requirem ents. Therefore, w e reverse the district court’s judgm ent, a nd we vacate the injunction.

While w e have now resolved those aspects of the parties’ dispute, Bair’s other claim s r e garding defects in Caltrans’

31 Caltrans invites u s to exercise our discretion to resolve Bair’s other clai m s, w hich t

he district court did not reach when it entered final judgm ent against Caltrans. See Bair , 385 F

. Supp. 3d at 898. We decline the invitation. S

ee Davis v. Nordstrom, Inc. , 755 F.3d 1089, 1094–95 (9th Cir. 2014).B AI R V

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consideration of other issues rem ain unresolved because the district court’s order that Caltrans m ust prepare an E IS m ade it unnecessary to do so. W e expect that the district court will
now expeditiously consider and dispose of tho se rem aining claim s on rem and.

REVERSED a nd REM AN D E D f o r f ur t he r proceedings not inconsistent w ith this Opinion.

WARDLAW , Circuit Judge, concurring “Although the environm ental assessm ent did not always
m ake [Caltrans’s] re a s o n ing explicit” and is “a decision o f less than ideal clarity,” “the agency’s path m ay reasonably be discerned.” A m. Wild Horse Campaign v. Bernhardt , 963 F.3d 1001 , 1 0 0 9 ( 9th Cir. 2020). Therefore, in light o f the adm inistrative record in this case, I concur in the m ajority opinion. C altrans did n ot violate NEPA because its reliance
on the EA was not arbitrary and capricious. I write separately to em phasize three points.
First, reviewing the “nightm arish ‘adm inistrative record’ in this case was a p ainful exercise. B air v. Ca l

. Sta te Dep’t of T ransp. , N o. C 17-06419 W HA, 2 019 W L 2644074, at *5 (N.D. Cal. June 27, 2019). When resolving th e rem aining claim s on rem and, the district court’s suggestion that Caltrans provide a “ fr e sh adm inistrative record

. . . with no incorporations by reference” seem s sensible. Id. at *5.
Second, and as Caltrans’s counsel ac knowledged at oral argum ent, if “significant new inform ation is discovered” during the proposed con s truction or if “substantial projectB AI R V

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. 23 changes are m ade,” Recording of October 13, 2 020 Oral Argum ent at 17:10–17:42, 1 Caltrans m ay well need to reevaluate its analysis an d potentially prepare an additional
r e v is ed E A or even an EIS. See 23 C.F.R. §§ 771. 1 2 9 , 771.130; see also Idaho Sporting Congress Inc. v. Alexander , 222 F.3d 562, 566 n.2 (9th Cir. 2000) (“NEPA im poses on federal agencies a continuing duty to supplem ent existing EAs and EISs in response to significant new circum stances o r inform ation relevant to environm ental concerns and bearing
on the p roposed action or its im p acts.” (internal quotation
m arks and citati o n om itted)); Price Road Neighborhood Ass’n, Inc. v. U.S. Dep’t of Transp. , 1 13 F .3d 1505, 1510 (9th Cir. 1997) (exam ining the F HWA NEPA fram ework and the continuing duty to supplem ent).

Third and relatedly, the road or h ighway construction that Caltrans has proposed h ere seem s likely to provide new data
on the effects of constru c t i o n on old-growth redwoods. Given that m

uch of the s c ientific evidence in the record is non-quantitative and d a t ed, I w ould expect that such data would prove im

portant to future decisions surrounding these historic trees, and—if that data becom es available during the project—to an y d ecision concerning the preparation o f a supplem ental EA or EIS.

So therefore, I respect fully concur, with slight reservations in these tum ultuous tim es.

1 https://tinyurl.com

/y39s2g6o (last visited Nov. 24, 2020).