PUBLISH

UNITED STATES COURT OF APPEALS

TENTH CIRCUIT 

PEOPLE FOR THE ETHICAL 

TREATMENT OF PROPERTY 

OWNERS, 

Plaintiff-Appellee, 

v. 

UNITED STATES FISH AND 

WILDLIFE SERVICE; DANIEL M. 

ASHE, acting in his official capacity 

as Director of the United States Fish 

and Wildlife Service; NOREEN 

WALSH, acting in her official 

capacity as Regional Director of the 

United States Fish and Wildlife 

Service’s Mountain-Prairie Region; 

UNITED STATES DEPARTMENT OF 

THE INTERIOR; RYAN ZINKE,*

Defendants-Appellants, 

and 

FRIENDS OF ANIMALS, 

 Intervenor Defendant- 

 Appellant. 

________________ 

Nos. 14-4151 & 14-4165 

 

 *

 Pursuant to Fed. R. App. P. 43(c)(2), recently confirmed Secretary of 

the Department of Interior, Ryan Zinke, is substituted for former Secretary of the 

Interior Sally Jewell. 

FILED 

United States Court of Appeals 

Tenth Circuit 

March 29, 2017

Elisabeth A. Shumaker 

Clerk of Court
2

DEFENDERS OF WILDLIFE; DAVID S. 

COHEN; ERIC M. FREEDMAN; 

STEPHEN GARDBAUM; STEPHEN 

GOTTLIEB; M. ISABEL MEDINA; 

STEVEN D. SCHWINN; 

ENVIRONMENTAL LAW 

PROFESSORS; WILLIAM C. BANKS; 

NATIONAL ASSOCIATION OF HOME 

BUILDERS; ANIMAL WELFARE 

INSTITUTE; WYOMING 

ASSOCIATION OF CONSERVATION 

DISTRICTS; CENTER FOR 

BIOLOGICAL DIVERSITY; WYOMING 

FARM BUREAU FEDERATION; 

HUMANE SOCIETY OF THE UNITED 

STATES; SIERRA CLUB; WYOMING 

STOCK GROWERS ASSOCIATION; 

WILDEARTH GUARDIANS; 

WYOMING WOOL GROWERS 

ASSOCIATION; UTAH FARM 

BUREAU FEDERATION; CATO 

INSTITUTE AND PROFESSORS OF 

CONSTITUTIONAL LAW; STATE OF 

UTAH; STATE OF ALASKA; STATE 

OF ARIZONA; STATE OF 

COLORADO; STATE OF IDAHO; 

STATE OF KANSAS; STATE OF 

MONTANA; STATE OF SOUTH 

DAKOTA; STATE OF WYOMING; 

STATE OF MICHIGAN; CHAMBER OF 

COMMERCE OF THE UNITED 

STATES AND THE NATIONAL 

FEDERATION OF INDEPENDENT 

BUSINESS; MOUNTAIN STATES 

LEGAL FOUNDATION; 
3

UNITED STATES SENATORS MIKE 

LEE, JAMES INHOFE, MIKE ENZI, 

DAVID VITTER, TED CRUZ, AND 

ORRIN HATCH AND CONGRESSMEN 

JASON CHAFFETZ, CHRIS STEWART, 

MIA LOVE, AND ROB BISHOP; 

CENTER FOR CONSTITUTIONAL 

JURISPRUDENCE, 

 Amici Curiae. 

Appeals from the United States District Court 

for the District of Utah 

(D.C. No. 2:13-CV-00278-DB) 

Anna T. Katselas, Attorney (John C. Cruden, Assistant Attorney General, David 

C. Shilton, and Mary Hollingsworth, Attorneys, of the U.S. Department of 

Justice, Environment and Natural Resources Division, Washington, D.C., with 

her on the briefs), for Defendants-Appellants. 

Michael Ray Harris, of Friends of Animals, Wildlife Law Program, Centennial, 

Colorado, for Intervenor Defendant-Appellant. 

Jonathan Wood (M. Reed Hopper, with him on the brief), of Pacific Legal 

Foundation, Sacramento, California, for Plaintiff-Appellee. 

Jason C. Rylander and Karimah Schoenhut of Defenders of Wildlife, 

Washington, D.C., filed an amici curiae brief for Defenders of Wildlife, Animal 

Welfare Institute, Center for Biological Diversity, Humane Society of the United 

States, Sierra Club, and Wildearth Guardians, in support of DefendantsAppellants. 

David M. Driesen, Unversity Professor, of Syracuse University College of Law, 

Syracuse, New York, filed an amici curiae brief for Constitutional Law 

Professors William C. Banks, David S. Cohen, Eric M. Freedman, Stephen 

Gardbaum, Stephen E. Gottlieb, M. Isabel Medina, and Steven D. Schwinn, in 

support of Defendants-Appellants. 
4

Daniel H. Lutz and Hope M. Babcock of Institute for Public Representation, 

Georgetown University Law Center, Washington, D.C., filed an amicus curiae 

brief for Environmental Law Professors in support of Defendants-Appellants. 

Thomas J. Ward and Jeffrey B. Augello of National Association of Home 

Builders, Washington, D.C., and Norman D. James, Fennemore Craig, P.C., 

Phoenix, Arizona, filed an amicus curiae brief in support of Plaintiff-Appellee. 

Karen Budd-Falen of Budd-Falen Law Offices, LLC, Cheyenne, Wyoming, filed 

an amici curiae brief for Wyoming Association of Conservation Districts, 

Wyoming Farm Bureau Federation, Wyoming Stock Growers Association, 

Wyoming Wool Growers Association, and Utah Farm Bureau Federation, in 

support of Plaintiff-Appellee. 

Ilya Shapiro and Julio Colomba, of Cato Institute, Washington, D.C., filed an 

amici curiae brief for Cato Institute and Professors of Constitutional Law, in 

support of Plaintiff-Appellee. 

Damien M. Schiff of Alston & Bird LLP, Sacramento, California, filed an amici 

curiae brief for United States Senators Mike Lee, James Inhofe, Mike Enzi, David 

Vitter, Ted Cruz, and Orrin Hatch and Congressmen Jason Chaffetz, Chris 

Stewart, Mia Love, and Rob Bishop in support of Plaintiff-Appellee. 

Sean D. Reyes, Utah Attorney General, and Bridget K. Romano, Utah Solicitor 

General, Anthony L. Rampton and Kathy A.F. Davis, Assistant Utah Attorneys 

General, Salt Lake City, Utah, Craig W. Richards, Attorney General, Juneau, 

Alaska, Mark Brnovich, Attorney General, Phoenix, Arizona, Cynthia Coffman, 

Attorney General, Denver, Colorado, Lawrence G. Wasden, Attorney General, 

Boise, Idaho, Derek Schmidt, Attorney General, Topeka, Kansas, Tim Fox, 

Attorney General, Helena, Montana, Marty Jackley, Attorney General, Pierre, 

South Dakota, and Peter K. Michael, Attorney General, Cheyenne, Wyoming, 

filed an amici curiae brief for the States of Utah, Alaska, Arizona, Colorado, 

Idaho, Kansas, Montana, South Dakota, and Wyoming in support of PlaintiffAppellee. 

Steven J. Lechner of Moutain States Legal Foundation, Lakewood, Colorado, 

filed an amicus curiae brief for Mountain States Legal Foundation in support of 

Plaintiff-Appellee. 

John C. Eastment, Anthony T. Caso, and Cristen Wohlgemuth of Center for 

Constitutional Jurisprudence, Orange, California, filed an amicus curiae brief for 

Center for Constitutional Jurisprudence in support of Plaintiff-Appellee. 
5

William S. Consovoy and J. Michael Connolly of Consovoy McCarthy PLLC, 

Arlington, Virginia; Patrick Strawbridge of Consovoy McCarthy PLLC, Boston, 

Massachusetts; Kate Comerford Todd and Sheldon Gilbert of U.S. Chamber 

Litigation Center, Inc., Washington, D.C.; and Karen R. Harned and Luke A. 

Wake of NFIB Small Business Legal Center, Washington, D.C., filed an amici 

curiae brief for the Chamber of Commerce of the United States and the National 

Federation of Independent Business in support of Plaintiff-Appellee. 

Before HOLMES, McHUGH, and MORITZ, Circuit Judges. 

HOLMES, Circuit Judge. 

 

 People for the Ethical Treatment of Property Owners (“PETPO”) 

challenges a regulation promulgated by the United States Fish and Wildlife 

Service (“FWS” or “Service”) pursuant to the Endangered Species Act (“ESA”). 

The challenged regulation prohibits the “take” of the Utah prairie dog, a purely 

intrastate species, on nonfederal land. The ESA defines “take” as meaning “to 

harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect.” 16 

U.S.C. § 1532(19). 

 The district court granted summary judgment for PETPO on the ground that 

neither the Commerce Clause nor the Necessary and Proper Clause of the 

Constitution authorizes Congress to regulate take of the Utah prairie dog on 

nonfederal land. FWS and intervenor-defendant Friends of Animals (“FoA”) 

appeal from that grant of summary judgment, arguing that the challenged 

regulation is authorized by both the Commerce Clause and the Necessary and 

Proper Clause, and that PETPO lacks standing. We hold that the district court 
6

correctly concluded that PETPO has standing, but erred in concluding that 

Congress lacked authority under the Commerce Clause to regulate (and authorize 

the Service to regulate) the take of the Utah prairie dog. 

I

A

 The purpose of the ESA is to conserve endangered and threatened species 

and the ecosystems on which they depend. See 16 U.S.C. § 1531(b). In order to 

effectuate this purpose, Congress tasked two executive officers with jointly 

implementing the Act: the Secretary of the Interior and the Secretary of 

Commerce. Id. § 1532(15). They, in turn, delegated their implementation 

responsibilities to, respectively, FWS and the National Marine Fisheries Service. 

 The ESA expressly defines the objects of its protections, that is, both 

“endangered species” and “threatened species.” An endangered species “is in 

danger of extinction throughout all or a significant portion of its range,” except 

for insect species determined to be pests “present[ing] an overwhelming and 

overriding risk to man.” Id. § 1532(6). A threatened species is one “which is 

likely to become an endangered species within the foreseeable future throughout 

all or a significant portion of its range.” Id. § 1532(20). 

 To protect these categories of species, the ESA “authorizes the Secretary of 

the Interior to list domestic or foreign species as endangered or threatened.” 

Wyo. Farm Bureau Fed’n v. Babbitt, 199 F.3d 1224, 1231 (10th Cir. 2000) (citing 

16 U.S.C. § 1533(a)–(b)). At least five factors are to be considered in listing a 
7

species as endangered or threatened: “(A) the present or threatened destruction, 

modification, or curtailment of its habitat or range; (B) overutilization for 

commercial, recreational, scientific or educational purposes; (C) disease or 

predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other 

natural or manmade factors affecting its continued existence.” 16 U.S.C. 

§ 1533(a)(1). “Once a species is so listed, it is afforded certain protections, and 

federal agencies assume special obligations to conserve, recover and protect that 

species.” Wyo. Farm Bureau Fed’n, 199 F.3d at 1231. 

 The “cornerstone” of the ESA’s protections is a section prohibiting the take 

of any endangered species without a permit or other authorization. Gibbs v. 

Babbitt, 214 F.3d 483, 487 (4th Cir. 2000) (citing 16 U.S.C. § 1538(a)(1)(B)). 

Pursuant to 16 U.S.C. § 1533(d), the Secretary of the Interior is authorized to 

extend the statutory prohibitions on take of endangered species to threatened 

species. See 16 U.S.C. § 1533(d) (“The Secretary may by regulation prohibit 

with respect to any threatened species any act prohibited under section 1538(a)(1) 

of this title, in the case of fish or wildlife . . . .”). FWS extended that cornerstone 

take prohibition to protect all threatened species. See 50 C.F.R. § 17.31 

(“General Rule 4(d)” or “General Rule”). More specifically, FWS’s General Rule 

4(d) prohibits the take of all species listed as threatened by incorporating as to 

those species the prohibitions applicable to endangered species under 50 C.F.R. 

§ 17.21, except when FWS issues a specific rule for a particular threatened 

species. See id.; see also 50 C.F.R. § 17.21 (setting forth take and other 
8

prohibitions with respect to endangered species). In such cases, the specific rule, 

or “special rule,” regarding the particular species takes precedence over General 

Rule 4(d), such that the General Rule’s blanket prohibition on take of threatened 

species no longer applies to that species and the special rule governs instead. 

See id. § 17.31(c). 

 The Utah prairie dog is a threatened species whose take is regulated by a 

special rule. The Utah prairie dog lives only in Utah and approximately seventy 

percent of the population is on nonfederal land. Originally listed as an 

endangered species under the ESA, Amendments to Lists of Endangered Fish and 

Wildlife, 38 Fed. Reg. 14678-01, 14678 (June 4, 1973) (codified as amended at 

50 C.F.R. § 17.11), the species was reclassified as threatened in 1984; at that 

time, the FWS issued a special rule to regulate its take, Final Rule to Reclassify 

the Utah Prairie Dog as Threatened, With Special Rule To Allow Regulated 

Taking, 49 Fed. Reg. 22330-01, 22330 (May 29, 1984) (codified as amended at 

50 C.F.R. § 17.40(g)). The special rule (“Special Rule 4(d)” or “Special Rule”) 

was amended in 1991, Final Rule to Amend Special Rule Allowing Regulated 

Taking of the Utah Prairie Dog, 56 Fed. Reg. 27438-01, 27438 (June 14, 1991) 

(codified as amended at 50 C.F.R. § 17.40(g)), and again in 2012, Revising the 

Special Rule for the Utah Prairie Dog, 77 Fed. Reg. 46158-01, 46158 (Aug. 2, 

2012) (codified at 50 C.F.R. § 17.40(g)). 

 Today, Special Rule 4(d) regulates the take of Utah prairie dog by limiting: 

(1) the permissible locations of such take to agricultural lands, properties within 
9

0.5 miles of conservation lands, and “areas where Utah prairie dogs create serious 

human safety hazards or disturb the sanctity of significant human cultural or 

burial sites[;]” (2) the permissible amount of such take; and (3) the permissible 

methods of such take. 50 C.F.R. § 17.40(g). In addition, the Special Rule 

authorizes incidental take that occurs as part of standard agricultural practices. 

See id. § 17.40(g)(5). 

 PETPO, a nonprofit organization, was founded by Utah “residents who 

suffer as a result of the regulation of Utah prairie dog take.” J.A. at 160 (Decl. of 

Derek Morton, filed Nov. 18, 2013). PETPO is comprised of more than 200 

“private property owners and other persons and entities subject to overly 

burdensome regulations,” id., who allege that they “have been prevented from 

building homes, starting small businesses, and, in the case of the local 

government, from protecting recreational facilities, a municipal airport, and the 

local cemetery from the Utah prairie dog’s maleffects,” Aplee.’s Br. at 3 

(citations omitted). 

B

 PETPO filed the instant action against FWS under the Administrative 

Procedure Act (“APA”), 5 U.S.C. § 551 et seq., alleging that neither the 

Commerce Clause nor the Necessary and Proper Clause authorizes Congress to 

regulate take of the Utah prairie dog on nonfederal land. PETPO requested both 

declaratory and injunctive relief against the regulation of Utah prairie dog take on 
10

nonfederal land. FoA filed a motion to intervene, and the district court granted 

the motion. 

 PETPO then moved for summary judgment. FWS cross-moved for 

summary judgment, defending the constitutionality of the challenged regulation 

under both the Commerce Clause and the Necessary and Proper Clause and 

arguing that PETPO lacks standing. The district court granted summary judgment 

for PETPO and denied summary judgment for FWS and FoA, concluding that: (1) 

PETPO has standing; (2) the Commerce Clause does not authorize Congress to 

regulate the take of a purely intrastate species (i.e., the Utah prairie dog) that has 

no substantial effect on interstate commerce; and (3) the Necessary and Proper 

Clause does not authorize Congress to regulate take of the Utah prairie dog 

because such regulation is not essential to the ESA’s economic scheme.

 FWS and FoA timely appealed. They raise two arguments on appeal: 

(1) PETPO lacks standing; and (2) both the Commerce Clause and the Necessary 

and Proper Clause authorize Congress to regulate take of the Utah prairie dog on 

nonfederal land. We hold that the district court correctly concluded that PETPO 

has standing, but erred in concluding that the challenged regulation is not 

authorized by the Commerce Clause. In light of our Commerce Clause holding, 

we have no need to opine regarding the merits of the district court’s Necessary 

and Proper Clause ruling, and do not do so. We accordingly reverse and remand 

for entry of summary judgment for FWS and FoA. 

II
11

 First, we conclude that PETPO has standing to challenge the 

constitutionality of the regulation. We review issues of standing de novo. S. 

Utah Wilderness All. v. Palma, 707 F.3d 1143, 1152 (10th Cir. 2013). To 

demonstrate standing, a plaintiff must show that “(1) it has suffered an ‘injury in 

fact’ that is (a) concrete and particularized and (b) actual or imminent, not 

conjectural or hypothetical; (2) the injury is fairly traceable to the challenged 

action of the defendant; and (3) it is likely, as opposed to merely speculative, that 

the injury will be redressed by a favorable decision.” Bronson v. Swensen, 500 

F.3d 1099, 1106 (10th Cir. 2007) (quoting Friends of the Earth, Inc. v. Laidlaw 

Envtl. Servs., Inc., 528 U.S. 167, 180–81 (2000)). In making this showing at the 

summary-judgment stage, a plaintiff is not entitled to depend on “mere 

allegations”—rather, he must “‘set forth’ by affidavit or other evidence ‘specific 

facts,’ which for purposes of the summary judgment motion will be taken to be 

true.” Lujan v. Defs. of Wildlife, 504 U.S. 555, 561 (1992) (quoting Fed. R. Civ. 

P. 56(e)). 

 The parties agree that the first two elements of standing are satisfied,1

 but 

FoA argues that the third element, redressability, is not. Specifically, FoA argues 

that PETPO’s alleged injuries are not redressable because if the district court 

were to grant the requested relief and strike down Special Rule 4(d), the absence 

 1

 And we agree, too. PETPO members presented affidavits that they 

suffered injuries in fact (the first element), and that their injuries are fairly 

traceable to FWS through its regulation of Utah prairie dog take (the second 

element). 
12

of a special rule regarding the Utah prairie dog would trigger General Rule 4(d) 

to govern take of that species, and the General Rule prohibits even more take than 

the Special Rule. Thus, FoA argues that “even if PETPO succeeds [at 

invalidating Special Rule 4(d)], stricter federal rules [i.e., General Rule 4(d)] 

would come into play that would bar all take of prairie dog on private land.” 

Aplt. FoA’s Opening Br. at 12. 

 As a preliminary matter, FoA is correct that General Rule 4(d) prohibits 

more take than Special Rule 4(d) because under the General Rule, take is 

prohibited completely unless the party first obtains a permit. See 50 C.F.R. 

§ 17.31(a); see also id. § 17.21(a), (c). In contrast, under the Special Rule, take 

of the Utah prairie dog is not prohibited completely, but regulated with regard to 

location, amount, and method. Id. § 17.40(g). Thus, while the General Rule 

prohibits all take of Utah prairie dog without a permit, the Special Rule carves 

out certain allowances for take without a permit. 

 However, the fact that the General Rule prohibits more take than the 

Special Rule is irrelevant for our purposes because PETPO’s suit, in substance, 

attacks not any particular regulation but Congress’s ability to authorize any 

regulation of Utah prairie dog take. See Ala.-Tombigbee Rivers Coal. v. 

Kempthorne, 477 F.3d 1250, 1271 (11th Cir. 2007) (considering Commerce 

Clause challenge to final rule listing the Alabama sturgeon as endangered under 

the theory that “Congress has exceeded the power granted to it under the 

Commerce Clause by authorizing protection of the Alabama Sturgeon”). To be 
13

sure, in its briefing and at oral argument, PETPO curiously characterizes its claim 

as attacking the Special Rule and disclaims any attack on the ESA. But our 

standing inquiry must focus on the substance of PETPO’s lawsuit. See Buchwald 

v. Univ. of N.M. Sch. of Med., 159 F.3d 487, 494 (10th Cir. 1998) (focusing on 

“the substance of [the plaintiff’s] complaint” and the fact that there was “no 

evidence in the record” to support her claim of standing). And, as a matter of 

logic, PETPO’s wish to attack the regulation of prairie dog take on Commerce 

Clause and Necessary and Proper grounds implicates 16 U.S.C. § 1533(d), which 

grants authority to the Secretaries of the Interior and of Commerce to issue regulations 

extending the take prohibitions of § 1538(a)(1) to threatened species. See 16 U.S.C. 

§ 1533(d). If Congress lacks such authority under the Commerce Clause or the 

Necessary and Proper Clause, then it stands to reason that § 1533(d) cannot authorize any

regulation of prairie dog take, and FWS could not enforce either the general or specific 

rule. 

 An examination of PETPO’s complaint, particularly the requested relief, 

clearly bears out this understanding of PETPO’s claim. First, the relief requested 

would apply to both rules (as they pertain to take of Utah prairie dogs on 

nonfederal land). PETPO’s requested relief is not limited to a particular FWS 

regulation; instead, both the declaratory and injunctive relief requested would 

expressly pertain to any federal prohibition on the take of Utah prairie dogs on 

nonfederal land. PETPO requests the following relief: 
14

 (1) for a declaration that the prohibition of the take of the 

Utah prairie dog on non-federal land is invalid under the [APA], 

because it is inconsistent with constitutional right, power, privilege, 

or immunity and not in accordance with law; 

 (2) for a declaration that the prohibition of the take of the 

Utah prairie dog is an invalid exercise of delegated legislative power 

under the United States Constitution, and that the Service is without 

authority to prohibit the take of the prairie dog on non-federal land; 

[and] 

 (3) for a permanent injunction preventing the Service from 

enforcing the prohibition of the take of the Utah prairie dog on nonfederal land[.] 

J.A. at 34.2

 By its terms, the requested relief would apply equally to the prohibition of 

Utah prairie dog take in General Rule 4(d) as to the prohibition of Utah prairie dog take 

in Special Rule 4(d); that is, granting the relief that PETPO seeks would necessarily make 

unenforceable both rules to the extent that they prohibit take of the Utah prairie dog on 

nonfederal land. 

 Moreover, this conclusion is also consistent with how PETPO expressly framed its 

claim for relief under the APA. In its complaint, PETPO ended that claim by stating that 

110. No enumerated power supports the regulation of the 

take of the Utah prairie dog on non-federal land. 

 111. The regulation of the take of the Utah prairie dog on 

non-federal land is neither necessary nor proper to the exercise of 

any power of the federal government. 

 112. Therefore, the regulation of the take of the Utah prairie 

dog on non-federal land is contrary to constitutional right, power, 

privilege, or immunity, 5 U.S.C. § 706(2)(B), as well as arbitrary, 

capricious, and contrary to law, 5 U.S.C. § 706(2)(A). The Service 

 

 2 PETPO also requests costs of litigation and “other relief as the Court 

may deem just and proper.” J.A. at 35. 
15

has no authority to require PETPO’s members to obtain a permit, or 

satisfy any other conditions, before taking the prairie dog on nonfederal land. 

J.A. at 32 (emphasis added). This last sentence in particular shows that although 

the vehicle for this suit is an APA claim, the gist of PETPO’s claim is that the 

Service does not have delegated authority to regulate the take of Utah prairie 

dogs because, under the Constitution, Congress has no such authority to delegate. 

Were PETPO to win on that claim and FWS nonetheless attempted to enforce the 

General Rule insofar as it prohibits prairie dog take, FWS could expect its 

enforcement activities to be justifiably enjoined by a district court. Indeed, the 

district court here expressly understood this to be the question presented on the 

merits. See J.A. at 200 (“At the heart of the dispute . . . is whether one of the 

enumerated powers in the Constitution authorizes Congress—and, through 

congressional delegation, [FWS]—to regulate take of the Utah prairie dog on 

non-federal land.”) (Mem. Decision & Order, filed Nov. 5, 2014). 

Further, it is unclear how a court could set aside the Special Rule’s 

prohibition on take but not the General Rule’s, because the Special Rule prohibits 

take only to the extent that it incorporates by reference the take prohibitions 

found in the General Rule. See 50 C.F.R. § 17.40(g)(1) (“Except as noted in . . . 

this [Special Rule], all prohibitions of [General Rule 4(d)] . . . apply to the Utah 

prairie dog.”). In other words—with the sole exception of its incorporation of the 

General Rule’s take prohibition—the Special Rule actually permits take only in 

certain locations, amounts, and methods. Thus, we are satisfied that if PETPO 
16

prevails on its claim that Congress lacks authority to prohibit take of the Utah 

prairie dog, neither FWS nor a private party bringing a citizen’s suit could 

enforce any prohibition on Utah prairie dog take.3

 For these reasons, the district court correctly concluded that PETPO has 

standing—more specifically, that its alleged injuries are redressable by its requested 

relief.

III

A

 We now turn to the merits, where PETPO challenges FWS’s prohibition on take of 

the Utah prairie dog on nonfederal land by arguing that Congress’s authorization of this 

regulation is unconstitutional because neither the Commerce Clause nor the Necessary 

and Proper Clause grants Congress power to so regulate.4

 In short, if Congress could 

not itself regulate take of the Utah prairie dog on nonfederal land, neither could it 

authorize the Secretary of the Interior to promulgate regulations so regulating the 

species. 

 

 3 And if we were to grant this requested relief, all sources of PETPO’s 

alleged injuries would be eliminated. Cf. Vill. of Arlington Heights v. Metro. 

Hous. Dev. Corp., 429 U.S. 252, 261–64 (1997) (finding standing even though 

the requested relief removed only one barrier—zoning requirements—from 

construction of a housing development because the remaining barriers—such as 

financing—were mere “uncertainties” rather than “absolute barriers,” which 

permitted the court to infer a “substantial probability” that the housing would be 

built if the zoning requirements were invalidated). 

4

 PETPO concedes that Congress has the power under the Property 

Clause, U.S. CONST. Art. IV, § 3, cl. 2, to regulate take of the Utah prairie dog on 

federal land. 
17

 The APA permits an aggrieved party to challenge and requires us to “hold 

unlawful and set aside” final agency action that is “contrary to constitutional 

right, power, privilege, or immunity.”5

 5 U.S.C. § 706(2)(b); Lincoln v. Vigil, 

508 U.S. 182, 195 (1993) (“[T]he APA contemplates, in the absence of a clear 

expression of contrary congressional intent, that judicial review will be available 

for colorable constitutional claims . . . .”). Although we generally grant 

considerable deference to agency action, “[w]e review de novo claims alleging 

constitutional abuse by an agency.” Burke v. Bd. of Governors of Fed. Reserve 

Sys., 940 F.2d 1360, 1367 (10th Cir. 1991); see also Copar Pumice Co. v. 

Tidwell, 603 F.3d 780, 802 (10th Cir. 2010) (“Because constitutional questions 

arising in a challenge to agency action under the APA ‘fall expressly within the 

domain of the courts,’ we review de novo whether agency action violated a 

claimant’s constitutional rights.” (quoting Darden v. Peters, 488 F.3d 277, 283–

84 (4th Cir. 2007))); cf. Solid Waste Agency of N. Cook Cty. v. U.S. Army Corps 

of Eng’rs, 531 U.S. 159, 172–73 (2001) (applying constitutional avoidance in 

construing statute rather than deferring to agency interpretation because a serious 

constitutional question was raised under the Commerce Clause by the agency’s 

interpretation of statute); Hernandez-Carrera v. Carlson, 547 F.3d 1237, 1249 

 5

 We note that neither FWS nor FoA challenges PETPO’s ability to 

use the APA to challenge the prohibition on take of Utah prairie dogs by asserting 

that such a prohibition exceeds Congress’s power under the Commerce Clause. 

Indeed, with the exception of FoA’s standing argument, the parties engage almost 

entirely on the merits of the Commerce Clause question. 
18

(10th Cir. 2008) (“It is well established that the canon of constitutional avoidance 

does constrain an agency’s discretion to interpret statutory ambiguities, even 

when Chevron deference would otherwise be due.”); U.S. West, Inc. v. FCC, 182 

F.3d 1224, 1231 (10th Cir. 1999) (“[D]eference to an agency interpretation is 

inappropriate not only when it is conclusively unconstitutional, but also when it 

raises serious constitutional questions.”). Accordingly, we review de novo 

whether Congress lacks power under the Commerce Clause to authorize the 

prohibition of Utah prairie dog take. 

B

 We conclude that the district court erred in holding that the challenged 

regulation is not authorized under the Commerce Clause, which gives Congress 

authority “[t]o regulate Commerce with foreign Nations, and among the several 

States, and with the Indian Tribes.” U.S. CONST. art. I, § 8, cl. 3. 

1

The district court concluded that the Commerce Clause does not authorize 

the regulation because the regulated activity—i.e., take of the Utah prairie dog on 

nonfederal land—does not have a substantial effect on interstate commerce. The 

court reasoned that: (1) take of the Utah prairie dog on nonfederal land is not 

commercial or economic activity, and the fact that the challenged regulation 

prohibits people “from engaging in commercial activities . . . is irrelevant,” J.A.

at 203–04; and (2) the value of the Utah prairie dog, whether biological, 
19

commercial, scientific, or through potential future effects, has too attenuated an 

effect on interstate commerce, if any at all. 

2

 The Commerce Clause authorizes Congress to regulate three categories of 

activity: (1) “use of the channels of interstate commerce”; (2) “instrumentalities 

of interstate commerce, or persons or things in interstate commerce”; and (3) 

“activities that substantially affect interstate commerce.” United States v. Lopez, 

514 U.S. 549, 558–59 (1995). “[T]he parties in the present dispute agree that the 

first two Lopez categories do not apply . . . .” J.A. at 202. Thus, we inquire only 

whether, under the third Lopez category, the activity regulated substantially 

affects interstate commerce. See Lopez, 514 U.S. at 558–59 (holding that 

“Congress’ commerce authority includes the power to regulate those activities 

having a substantial relation to interstate commerce, i.e., those activities that 

substantially affect interstate commerce” (emphases added) (citation omitted)). 

 To determine whether a regulated activity substantially affects interstate 

commerce, we ask “whether Congress had a rational basis to find that the 

regulated activity, taken in the aggregate, would substantially affect interstate 

commerce.” United States v. Patton, 451 F.3d 615, 623 (10th Cir. 2006) 

(emphasis added). The Supreme Court has “stress[ed] that the task before us is a 

modest one. We need not determine whether respondents’ activities, taken in the 

aggregate, substantially affect interstate commerce in fact, but only whether a 
20

‘rational basis’ exists for so concluding.” Gonzales v. Raich, 545 U.S. 1, 22 

(2005) (quoting Lopez, 514 U.S. at 557). 

 Under the third Lopez category, Congress has the “power to regulate purely 

local activities that are part of an economic ‘class of activities’ that have a 

substantial effect on interstate commerce.” Raich, 545 U.S. at 17; accord Taylor 

v. United States, --- U.S. ----, 136 S. Ct. 2074, 2080 (2016). Consequently, 

“where a general regulatory statute bears a substantial relation to commerce, the 

de minimis character of individual instances arising under that statute is of no 

consequence.” Lopez, 514 U.S. at 558; see also Taylor, 136 S. Ct. at 2079 

(“[A]ctivities . . . that ‘substantially affect’ commerce . . . may be regulated so 

long as they substantially affect interstate commerce in the aggregate, even if 

their individual impact on interstate commerce is minimal.” (emphasis added));

Raich, 545 U.S. at 23 (distinguishing between regulation that “f[alls] outside 

Congress’ commerce power in its entirety” and regulation that constitutes an 

“individual application[] of a concededly valid statutory scheme”). As a result, 

the Supreme Court has made clear that “[t]he question . . . is whether Congress’ . 

. . policy judgment, i.e., its decision to include [a] narrower ‘class of activities’ 

within [a] larger regulatory scheme, was constitutionally deficient,” or whether 

“the subdivided class of activities . . . was an essential part of the larger 

regulatory scheme.” Raich, 545 U.S. at 26–27; see also id. at 28 (“The 

congressional judgment that an exemption for . . . a significant segment of the 
21

total market would undermine the orderly enforcement of the entire regulatory 

scheme is entitled to a strong presumption of validity.”). 

Moreover, the Court has underscored that the fact that a regulated activity 

is noncommercial or “trivial by itself” is “not a sufficient reason for removing [it] 

from the scope of [otherwise valid] federal regulation.”6

 Raich, 545 U.S. at 20; 

see id. at 17 (“[E]ven if appellee’s activity be local and though it may not be 

regarded as commerce, it may still, whatever its nature, be reached by Congress 

if it exerts a substantial economic effect on interstate commerce.” (emphasis 

added) (quoting Wickard v. Filburn, 317 U.S. 111, 125 (1942))); id. at 22 (“That 

the regulation ensnares some purely intrastate activity is of no moment. As we 

have done many times before, we refuse to excise individual components of that 

larger scheme.”); see also Taylor, 136 S. Ct. at 2081 (“[I]t makes no difference 

under our cases that any actual or threatened effect on commerce in a particular 

case is minimal.” (emphasis added)). 

 In short, the Commerce Clause authorizes regulation of noncommercial, 

purely intrastate activity that is an essential part of a broader regulatory scheme 

 6

 In addition to arguing that the challenged regulation is constitutional 

under the Raich framework, FWS argues that the regulation substantially affects 

interstate commerce because the activity at which it is directed is commercial or 

economic in nature. See, e.g., Patton, 451 F.3d at 623 (noting that this criterion 

“determines whether the regulated activity falls within the definition of 

‘commerce.’ If so, . . . there is a heavy—perhaps in reality irrebuttable—

presumption that it affects more states than one, and falls within congressional 

power.”). However, we need not and do not reach this argument because, as we 

explain below, our holding under the Raich framework fully resolves this appeal. 
22

that, as a whole, substantially affects interstate commerce (i.e., has a substantial 

relation to interstate commerce). Therefore, to uphold the challenged regulation 

here, we need only conclude that Congress had a rational basis to believe that 

such a regulation constituted an essential part of a comprehensive regulatory 

scheme that, in the aggregate, substantially affects interstate commerce.

a

 We conclude that Congress had a rational basis to believe that regulation of 

the take of the Utah prairie dog on nonfederal land is an essential part of the 

ESA’s broader regulatory scheme which, in the aggregate, substantially affects 

interstate commerce. We first examine the ESA’s status as a comprehensive 

regulatory scheme substantially affecting commerce and then turn to whether 

Congress had a rational basis to believe that regulation of take of the Utah prairie 

dog on nonfederal land is an essential part of that scheme. 

 As a preliminary matter, PETPO argues that we must employ a substantial 

effects analysis with regard to regulation of take of the Utah prairie dog alone, 

not with respect to all species or the ESA generally. See Aplee.’s Br. at 27–31. 

Specifically, PETPO contends that its claim is like those presented in Lopez and 

Morrison, because PETPO facially challenges a provision rather than “an 

application to a particular subset of activity, as in Raich.” Id. at 28. In essence, 

PETPO argues that because it characterizes its claim as a facial challenge to a 

regulatory provision, the concerns implicated in Raich do not apply and so we 

must engage in a straightforward substantial effects analysis as to the regulation 
23

of take of the Utah prairie dog alone. But this argument misconstrues the 

standard that Raich establishes and the substance of the claim that PETPO 

actually asserts. 

 As established supra, the real crux of PETPO’s challenge is not a challenge 

to any particular FWS regulation but to Congress’s power to authorize regulation 

of the Utah prairie dog. Although PETPO is, in a sense, correct that the 

prohibition on take of the Utah prairie dog is “a particular challenged provision,” 

Aplee.’s Br. at 29, this prohibition finds its place within the broader regulatory 

scheme of the ESA’s protections of endangered and threatened species. More 

specifically, the prohibition at issue is an instance of Congress’s broad 

authorization to use regulations to extend the take protections that endangered 

species enjoy to those listed as threatened. See 16 U.S.C. § 1533(d). 

 PETPO points to no authority suggesting that a challenge such as this 

should be considered under a narrow application of the substantial effects test 

rather than the Raich comprehensive regulatory scheme framework. PETPO 

mischaracterizes FWS’s and FoA’s arguments as suggesting that the substantial 

effects test must be applied “to an enactment as a whole, rather than a particular 

challenged provision.” Aplee.’s Br. at 29. In doing so, PETPO cites Morrison, 

Lopez, and our own decision in Patton, arguing that in each case an individual 

provision was examined despite the fact that it was part of a larger piece of 

legislation. See id. at 29–30. But the legislation at issue in those cases did not 

constitute comprehensive regulatory schemes such as the CSA in Raich or the 
24

ESA in the present case. The CSA “repealed most of the earlier antidrug laws in 

favor of a comprehensive regime to combat the international and interstate traffic 

in illicit drugs.” Raich, 545 U.S. at 12. 

 In contradistinction to the CSA, the Court pointed to the Gun-Free School 

Zones Act of 1990 that Lopez struck down as being “at the opposite end of the 

regulatory spectrum.” Id. at 24; see also Lopez, 514 U.S. at 561 (“Section 922(q) 

is not an essential part of a larger regulation of economic activity, in which the 

regulatory scheme could be undercut unless the intrastate activity were regulated. 

It cannot, therefore, be sustained under our cases upholding regulations of 

activities that arise out of or are connected with a commercial transaction, which 

viewed in the aggregate, substantially affects interstate commerce.”). Despite the 

fact that the Gun-Free School Zones Act of 1990 was part of a single, large 

enactment—the Crime Control Act of 1990, Pub. L. 101-647, 104 Stat. 4789—the 

Court had no difficulty recognizing that this broader enactment was not a 

comprehensive regulatory scheme, dealing as it did with subjects as diverse as 

international money laundering, child abuse, and victims’ rights. See 104 Stat. at 

4789, 4792 (for example, Title I of the Crime Control Act of 1990 addresses 

international money laundering, while Title II is the Victims of Child Abuse Act 

of 1990). Indeed, the Court in both Lopez and Raich looked past the larger 

enactment and characterized the Gun-Free School Zones Act as an independent 

statute. Lopez, 514 U.S. at 561 (“Section 922(q) is a criminal statute . . . .”); 

Raich, 545 U.S. at 23 (describing the Gun-Free School Zones Act as “a brief, 
25

single-subject statute”); see also Crime Control Act of 1990 § 1702, 104 Stat. at 

4844 (containing the Gun-Free School Zones Act of 1990 in Title XVII of the 

enactment, bearing the heading, “General Provisions,” which contains provisions 

concerning railroad police officers and the use of private prisons for federal 

prisoners, as well as a directive to the Sentencing Commission to produce a report 

on mandatory minimum sentences). 

 The prohibition against felon possession of body armor we dealt with in 

Patton and the Violence Against Women Act of 1994 that Morrison addressed are 

equally distinguishable from comprehensive regulatory schemes such as the CSA 

or ESA. See Violent Crime Control and Law Enforcement Act of 1994, Pub. L. 

No. 103-322, § 2, 108 Stat. 1796, 1796–1807 (table of contents of the enactment 

containing the Violence Against Women Act as one of thirty-three separate titles 

addressing a variety of subjects); 21st Century Department of Justice 

Appropriations Authorization Act, Pub. L. No. 107-273, § 1(b), 116 Stat. 1758, 

1758–62 (2002) (table of contents of the enactment containing the James Guelff 

and Chris McCurley Body Armor Act of 2002 along with, inter alia, provisions 

addressing appropriations for the Department of Justice, drug treatment and 

prevention, and the Boys and Girls Clubs of America). That all of these laws 

were passed as parts of larger congressional enactments is immaterial under 

Raich, which concerns comprehensive regulatory regimes. 

 PETPO concedes that because “all classes of activities can be subdivided to 

find that they don’t substantially affect interstate commerce, excising a particular 
26

party’s activity could potentially subject the Commerce Clause to death by a 

thousand cuts.” Aplee.’s Br. at 28. Although the language of “excising a 

particular party’s activity” is at least not linguistically congruent with Raich, 

which speaks of “individual instances of [a] class,” 545 U.S. at 17, 23, we would 

do well to heed the danger that PETPO itself warns us about. Application of the 

rule that PETPO suggests would lead to just such a lingering death for the ESA—

and likely for other regulatory schemes—insofar as every individual regulation 

passed within a larger regulatory scheme would be subject to a narrowly applied 

substantial effects test—a result that Raich directly forecloses. It should not 

surprise then, that every circuit to have addressed the constitutionality of take 

prohibitions under the ESA has, in effect, rejected such an approach. 

 More specifically, every federal appellate court that has addressed whether 

the ESA is a comprehensive scheme substantially affecting commerce has 

aggregated its effects on all threatened and endangered species.7

 See San Luis & 

 7

 While it is true that many of these cases concern the statutory

protections granted to species listed as endangered rather than prohibitions 

established by agency rulemaking, that distinction is immaterial for the Raich 

analysis, insofar as species are also listed as endangered by rulemaking. See 50 

C.F.R. § 17.11 (listing endangered and threatened wildlife). Indeed, one case, 

Alabama-Tombigbee Rivers Coalition, expressly dealt with a challenge to the 

decision to list a species as endangered, not the application of the statutory 

protections to that species. See 477 F.3d at 1271–72 (“The Coalition’s third 

contention is that the Final Rule should be vacated because Congress has 

exceeded the power authorized to it under the Commerce Clause by authorizing 

protection of the Alabama sturgeon, which the Coalition characterizes as an 

intrastate, noncommercial species.”). Indeed, PETPO itself concedes that the fact 

that here “the activity is regulated under a regulation rather than a statutory 

provision” amounts to “a distinction without a difference.” Aplee.’s Br. at 28. 
27

Delta-Mendota Water Auth. v. Salazar, 638 F.3d 1163, 1175–76 (9th Cir. 2011) 

(“Pursuant to Raich, when a statute is challenged under the Commerce Clause, 

courts must evaluate the aggregate effect of the statute (rather than an isolated 

application) in determining whether the statute relates to ‘commerce or any sort 

of economic enterprise.’ . . . We and other courts have discussed at length why 

the protection of threatened or endangered species implicates economic 

concerns.”); Ala.-Tombigbee Rivers Coal., 477 F.3d at 1273 (“If the process of 

listing endangered species is ‘an essential part of a larger regulation of economic 

activity,’ then whether that process ‘ensnares some purely intrastate activity is of 

no moment.’ . . . The [ESA] prohibits all interstate and foreign commerce in 

endangered species.” (quoting Raich, 545 U.S. at 24)); GDF Realty Invs., Ltd. v. 

Norton, 326 F.3d 622, 639 (5th Cir. 2003) (determining whether “the larger 

regulation [is] directed at activity that is economic in nature” and noting that 

“ESA’s protection of endangered species dtw10 is economic in nature” and that 

“ESA’s drafters were concerned by the ‘incalculable’ value of the genetic 

heritage that might be lost absent regulation,” as well as observing that the 

majority of takes of species “result from economic activity” (emphasis added)); 

Nat’l Ass’n of Home Builders v. Babbitt, 130 F.3d 1041, 1046 (D.C. Cir. 1997) 

(“[W]e may look not only to the effect of the extinction of the individual 

endangered species at issue in this case, but also to the aggregate effect of the 

extinction of all similarly situated endangered species.”); cf. Markle Interests, 

L.L.C. v. U.S. Fish & Wildlife Serv., 827 F.3d 452, 475–77 (5th Cir. 2016) 
28

(aggregating all ESA critical-habitat designations and upholding FWS 

designation of private, purely intrastate land for purely intrastate frog species 

under the Commerce Clause). 

 PETPO next argues that the ESA “is a comprehensive scheme to provide 

for environmental conservation, not [to] regulate a market.” Aplee.’s Br. at 38.8

 

 8

 PETPO appears to proceed under the theory that Raich implicates not 

the Commerce Clause alone but also the Necessary and Proper Clause, insofar as 

this argument appears in the section of its brief on the Necessary and Proper 

clause. See Aplee.’s Br. at 31–41. The district court appears to have operated 

under a similar assumption, holding as it did that the prohibition on take of the 

Utah prairie dog was “not necessary to the ESA’s economic scheme.” J.A. at 

207. 

 In Raich, the Court stated that a comprehensive regulatory scheme that 

substantially affects interstate commerce is “well within [Congress’s] authority to 

‘make all Laws which shall be necessary and proper’ to ‘regulate Commerce 

. . . among the several States.’” 545 U.S. at 22 (quoting U.S. CONST. art. I, § 8). 

In upholding the constitutionality of the statute at issue in that case, however, the 

Court analyzed only Commerce Clause jurisprudence to conclude that the 

regulatory scheme substantially affected interstate commerce; the Court did not 

conduct a separate inquiry under the Necessary and Proper Clause. Only Justice 

Scalia’s concurring opinion in Raich, joined by no other justice, squarely 

considered the case as implicating the Necessary and Proper Clause. See 545 

U.S. at 34 (Scalia, J., concurring in the judgment) (opining that the substantial 

effects analysis of intrastate activities “derives from the Necessary and Proper 

Clause”). Further, we have before recognized that Raich is concerned with the 

third prong of traditional Commerce Clause analysis: “The Supreme Court’s 

decisions in Lopez, United States v. Morrison, and Raich all hinged on 

interpretation of the third category of [Commerce Clause analysis].” Patton, 451 

F.3d at 623 (citation omitted). But see United States v. Carel, 668 F.3d 1211, 

1219 (10th Cir. 2011) (suggesting that Raich is a Necessary and Proper Clause 

case). 

 Because PETPO seemingly understands Raich to be a Necessary and Proper 

Clause case, its arguments relevant to Raich appear in that section of its brief. 

While we perform our Raich analysis under the Commerce Clause, we present 

and address PETPO’s arguments—irrespective of where they are found in its 
29

This argument rests on the premise that, under Raich,

9

 Congress may only reach 

intrastate activity “which, if beyond [Congress’s] grasp, would frustrate a 

comprehensive regulatory scheme’s ability to function as a regulation of 

commerce.” Id. at 32 (emphasis added) (citing, inter alia, Raich, 545 U.S. at 22). 

But this premise is flawed and improperly narrows the standard that Raich

establishes. 

 As an initial matter, the passage that PETPO cites from Raich as support 

for this argument concerns whether a rational basis exists for believing that 

regulation of intrastate activity was essential to the CSA, not whether the 

comprehensive scheme of the CSA itself involved the regulation of commerce. 

545 U.S. at 22 (“[W]e have no difficulty concluding that Congress had a rational 

basis for believing that failure to regulate the intrastate manufacture and 

possession of marijuana would leave a gaping hole in the CSA.”). Further, the 

Ninth Circuit has persuasively rejected such a narrow reading of Raich. 

Specifically, in San Luis & Delta-Mendota Water Authority, the court rejected the 

argument that the ESA does not have a “substantial effect” on interstate 

 

briefing—insofar as they are relevant to that analysis. We would also note that 

were we to proceed instead under the assumption that Raich was decided under 

the Necessary and Proper Clause, our ultimate conclusion—that the prohibition 

on take of the Utah prairie dog is constitutional—would remain unchanged. 

9

 PETPO also cites National Federation of Independent Business v. 

Sebelius, 567 U.S. 519, 132 S. Ct. 2566, 2591–92 (2012) for this proposition, but 

the cited portion of Chief Justice Robert’s opinion was joined by no other 

member of the Court. 
30

commerce because, unlike the Controlled Substance Act upheld in Raich, it “is 

not a ‘comprehensive economic regulatory scheme.’” San Luis, 638 F.3d at 1177 

(emphasis added). The Ninth Circuit explained that “[t]he Supreme Court has 

never required that a statute be a ‘comprehensive economic regulatory scheme’ or 

a ‘comprehensive regulatory scheme for economic activity’ in order to pass 

muster under the Commerce Clause. Indeed, it has never used those terms.” Id. 

The court continued that “[t]he only requirement—which was expressly detailed 

in Raich—is that the ‘comprehensive regulatory scheme’ have a ‘substantial 

relation to commerce.’” Id. (quoting Raich, 545 U.S. at 17). We agree with the 

Ninth Circuit on this, and so consider whether the ESA has a substantial relation 

to interstate commerce, and conclude that it does. 

PETPO wisely does not even attempt to dispute this; the substantial relationship 

between the ESA and interstate commerce is patent. First, regulation of take of 

endangered and threatened species is directly related to—indeed, arguably inversely 

correlated with—economic development and commercial activity. See 16 U.S.C. 

§ 1531(a)(1) (Congress’s finding and declaration of purpose that “various species of fish, 

wildlife, and plants in the United States have been rendered extinct as a consequence of 

economic growth and development untempered by adequate concern and conservation”); 

H.R. Rep. No. 93-412 (1973), reprinted in A Legislative History of the Endangered 

Species Act of 1973, as Amended in 1976, 1977, 1978, 1979, and 1980 [hereinafter A 

Legislative History of the Endangered Species Act], at 141 (1982) (“The threat to animals 

may arise from a variety of sources; principally pollution, destruction of habitat and the 
31

pressures of trade.”). In other words, the necessity of putting into place the ESA’s 

protections was engendered in part by the excesses of commerce, and the statute acts as a 

brake on economic activity, as confirmed by the harms that underlie PETPO’s standing. 

 Second, Congress’s purposes in enacting the ESA were to conserve species by 

restricting commerce and to promote long-term commerce by conserving species. See 

H.R. Rep. No. 93-412, reprinted in A Legislative History of the Endangered Species Act, 

at 144–45 (describing how the profit motive can incentivize the conservation of species 

and the potential for unknown commercial uses should engender appropriate caution, 

“[t]he institutionalization of that caution lies at the heart of [the ESA]”); cf. S. Rep. No. 

91-526, at 3 (1969), as reprinted in 1969 U.S.C.C.A.N. 1413, 1415 (stating that the 

protections offered by a predecessor to the ESA could “permit the regeneration of [an 

exploited] species to a level where controlled exploitation can be resumed,” thus creating 

“profit from the trading and marketing of that species for an indefinite number of years, 

where otherwise it would have been completely eliminated from commercial channels”). 

Thus, while the ESA’s prohibitions may act as a short-term brake on economic activity, 

the statutory scheme was intended to promote commercial activity in the long run. 

 And third, the ESA’s prohibitions help fuel an illegal wildlife trade that generates 

$5–8 billion annually—an illegal market second in size only to the illegal narcotics 

market. Because “Congress’ power to regulate commerce includes the power to prohibit 

commerce,” whether the targeted market “is a lawful market that Congress sought to 

protect and stabilize” or “an unlawful market that Congress sought to eradicate” “is of no 
32

constitutional import.” Raich, 545 U.S. at 19 n.29. These are salient reasons why the 

ESA substantially affects interstate commerce. 

 Next, we conclude that Congress had a rational basis to believe that providing for 

the regulation of take of purely intrastate species like the Utah prairie dog is essential to 

the ESA’s comprehensive regulatory scheme. Approximately sixty-eight percent of 

species that the ESA protects exist purely intrastate;10 thus, piecemeal excision of 

purely intrastate species would severely undercut the ESA’s conservation 

purposes.

11 Put another way, excising purely intrastate species “would leave a 

gaping hole in the” ESA. Raich, 545 U.S. at 22; see also Ala.-Tombigbee Rivers 

Coal., 477 F.3d at 1275 (“Because a species’ scientific or other commercial value 

is not dependent on whether its habitat straddles a state line, Congress had good 

 10 FWS generated this estimate and PETPO has not challenged it. We 

discern nothing in the record that calls into doubt its accuracy. 

11 PETPO argues that “there’s no reasonable basis to conclude that” the 

government’s inability to regulate take of the Utah prairie dog “would frustrate 

the government’s ability to regulate the market for any commodity.” Aplee.’s Br. 

at 35. But this argument is based on the same narrow reading of Raich that we 

rejected supra. The relevant question is not whether the inability to regulate take 

of the Utah prairie dog alone would undermine the ESA but whether the inability 

to regulate take of intrastate species more generally would undermine the ESA. 

See, e.g., GDF Realty Invs., 326 F.3d at 640 (concluding that “Cave Species takes 

may be aggregated with all other ESA takes” because otherwise the ESA would 

be undermined given “the interdependence of species [that] compels the 

conclusion that regulated takes under ESA do affect interstate commerce”). 

Applying Raich narrowly to the FWS’s prohibition of take of the Utah prairie 

dog, rather than more generally to the statutory authorization for such take 

regulations with respect to purely intrastate species, leads to a “death by a 

thousand cuts” of the ESA, to use PETPO’s colorful phrase. Aplee.’s Br. at 28. 
33

reason to include all species within the protection of the Act. It did not behave 

irrationally by taking the broader approach.”). 

 Every one of our sister circuits that has addressed this issue has agreed that 

regulation of purely intrastate species is an essential part of the ESA’s regulatory 

scheme. See GDF Realty, 326 F.3d at 640 (concluding that regulation of purely 

intrastate Cave Species takes “is an essential part of” ESA’s larger regulatory 

scheme); Gibbs, 214 F.3d at 487 (“This regulation [prohibiting take of red 

wolves] is also sustainable as ‘an essential part of a larger regulation of economic 

activity, in which the regulatory scheme could be undercut unless the intrastate 

activity were regulated.’” (quoting Lopez, 514 U.S. at 561)); see also Markle 

Interests, 827 F.3d at 476–78 (upholding FWS critical-habitat designations—in 

that case, of purely intrastate land for a purely intrastate species—under the 

Commerce Clause because such regulation is an essential part of ESA’s 

regulatory scheme); Ala.-Tombigbee, 477 F.3d at 1274 (“Just as it is apparent that 

the ‘comprehensive scheme’ of species protection contained in the Endangered 

Species Act has a substantial effect on interstate commerce, it is clear that the 

listing process is ‘an essential part’ of that ‘larger regulation of economic 

activity.’” (quoting Raich, 545 U.S. at 22, 24)). We agree with these courts that 

Congress had a rational basis to conclude that providing for the protection of 

purely intrastate species is essential to the ESA’s comprehensive regulatory 

scheme. 
34

 And, having reached such a determination, courts appear to be led 

ineluctably to conclude that Congress has authority under the Commerce Clause 

to regulate purely intrastate species, including regulating the take thereof, under 

the ESA—either through a particular application of the ESA itself or through an 

agency regulation as here. See Markle Interests, 827 F.3d at 476–78 (upholding 

designation of private, intrastate land as critical habitat for a purely intrastate 

frog species under the Commerce Clause as an essential part of ESA’s 

comprehensive regulatory scheme); San Luis & Delta-Mendota Water Auth., 638 

F.3d at 1174–77 (upholding regulation of take of purely intrastate, 

noncommercial delta smelt as essential part of ESA’s comprehensive regulatory 

scheme); Ala.-Tombigbee Rivers Coal., 477 F.3d at 1271 (upholding regulation of 

purely intrastate, noncommercial Alabama sturgeon as essential part of ESA’s 

comprehensive regulatory scheme); GDF Realty Invs., Ltd., 326 F.3d at 638–41 

(upholding regulation of take of purely intrastate Cave Species as essential to 

ESA’s comprehensive regulatory scheme); Gibbs, 214 F.3d at 488, 492–98 

(holding that take of forty-one purely intrastate red wolves is economic activity 

that substantially affects interstate commerce, and that regulation of that take is 

an essential part of ESA’s comprehensive regulatory scheme); see also Nat’l 

Ass’n of Home Builders, 130 F.3d at 1052–57; see also id. at 1058 (Henderson, J., 

concurring) (stating that regulation of take of a purely intrastate fly species 

substantially affects interstate commerce by preventing loss of biodiversity and 

regulating interstate commercial development). Indeed, the facts of many of 
35

these cases closely track the present case, insofar as they concern challenges to 

regulation under the ESA of activity on nonfederal land. See Markle Interests, 

827 F.3d at 458–59; GDF Realty Invs., Ltd., 326 F.3d at 624–26; Gibbs, 214 F.3d 

at 489; Nat’l Ass’n of Home Builders, 130 F.3d at 251. 

 Finding the foregoing authority persuasive, we likewise conclude that the 

regulation on nonfederal land of take of a purely intrastate species, like the Utah 

Prairie dog, under the ESA is a constitutional exercise of congressional authority 

under the Commerce Clause. And if Congress could itself regulate take of the 

Utah prairie dog on nonfederal land, it could also constitutionally authorize the 

Secretary of the Interior to promulgate regulations to achieve this end. Because 

we uphold this regulatory exercise under an enumerated power, the Commerce 

Clause, we need not consider its constitutionality under the Necessary and Proper 

Clause. “[I]f it is not necessary to decide more, it is necessary not to decide 

more.” PDK Labs. Inc. v. DEA, 362 F.3d 786, 799 (D.C. Cir. 2004), quoted in 

Valley Forge Ins. Co. v. Health Care Mgmt. Partners, Ltd., 616 F.3d 1086, 1094 

(10th Cir. 2010) (“Judicial restraint, after all, usually means answering only the 

questions we must, not those we can.”). 

III

 In sum, we REVERSE and REMAND with instructions to enter judgment 

for FWS and FoA.