Amicus Curiae Brief — Department of the Interior, et al., Petitioners v. Shoshone-Bannock Tribes of the Fort Hall Reservation, et al.

No. 26-96, 26-109

In The

Supreme Court of the United States

DEPARTMENT OF THE INTERIOR, et al.,

Petitioners,

v.

SHOSHONE-BANNOCK TRIBES OF THE FORT HALL

RESERVATION, et al.,

Respondents.

J.R. SIMPLOT COMPANY, LLC,

Petitioner,

v.

SHOSHONE-BANNOCK TRIBES OF THE FORT HALL

RESERVATION, et al.,

Respondents.

On Petition for a Writ of Certiorari to the United

States Court of Appeals for the Ninth Circuit

BRIEF OF IDAHO GOVERNOR BRAD LITTLE,

THE STATE OF IDAHO, NEVADA GOVERNOR

JOE LOMBARDO, AND UTAH GOVERNOR

SPENCER J. COX AS AMICI CURIAE IN

SUPPORT OF PETITIONERS

RAÚL R. LABRADOR

Attorney General

JOY M. VEGA

Deputy Attorney

General, Chief of

Energy & Natural

Resource Division

MICHAEL A. ZARIAN

Solicitor General

Counsel of Record

IDAHO OFFICE OF THE

ATTORNEY GENERAL

700 W. Jefferson St.

Suite 210

Boise, Idaho 83720

(208) 334-2400

michael.zarian@ag.idaho.gov

ANDREW SNOOK

General Counsel

OFFICE OF GOVERNOR

BRAD LITTLE

Counsel for Amici Curiae

i

TABLE OF CONTENTS

Page

TABLE OF AUTHORITIES .......................................ii

INTERESTS OF AMICI CURIAE .............................. 1

SUMMARY OF THE ARGUMENT ............................ 2

ARGUMENT ............................................................... 3

I. If allowed to stand, the Ninth Circuit’s

decision would significantly harm Idaho.........3

A. Idaho will be harmed if the land exchange

at issue in this case is unwound. ................3

B. Idaho will be harmed by the broader

impact of the Ninth Circuit’s holding.........5

C. Idaho’s ability to affect and benefit from

federal land policy is diminished by the

Ninth Circuit’s holding. ............................11

CONCLUSION .......................................................... 13

ii

TABLE OF AUTHORITIES

Cases

Page(s)

Falls City v. Missouri Pac. R. Co.,

453 F.2d 771 (8th Cir. 1971)..................................9

Leo Sheep Co. v. United States,

440 U.S. 668 (1979) ................................................7

United States v. Coleman,

390 U.S. 599 (1968) ................................................3

Statutes

43 U.S.C. § 1701 ....................................................7, 11

43 U.S.C. § 1712 ........................................................12

43 U.S.C. § 1716 ....................................................8, 12

43 U.S.C. § 1720 ........................................................12

Act of Aug. 15, 1894, ch. 290, § 16,

28 Stat. 286 ............................................................7

Act of June 6, 1900, ch. 813,

31 Stat. 672 ........................................................2, 5

Act of Mar. 3, 1891, ch. 543, § 22,

26 Stat. 989 ............................................................7

Act of July 13, 1892, ch. 164,

27 Stat. 120 ............................................................7

Idaho Admission Act § 5(c)(3)(B),

26 Stat. 215 ............................................................9

Southern Nevada Public Land Management Act,

Pub. L. 105–263, § 4(a) (October 19, 1998) .........10

iii

TABLE OF AUTHORITIES—Continued

Page(s)

Other Authorities

1 The Records of the Federal Convention of 1787

(Max Farrand ed., 1911) ........................................1

29 Cong. Rec. 365 (1896) .............................................6

Amy Alonzo, Will the release of federal land help

Nevada’s affordable housing crisis? It depends,

The Nev. Indep. (June 1, 2025) ...........................10

Annual Estimates of the Resident Population for

Incorporated Places in Idaho: April 1, 2020 to

July 1, 2025 (SUB-IP-EST2025-POP-16),

U.S. Census Bureau, Population Division

(May 2026) .............................................................3

Availability for the Final Environmental Impact

Statement for the Proposed Blackrock Land

Exchange, 85 Fed. Reg. 31804 (May 27, 2020) ...13

Carol Hardy Vincent & Laura A. Hanson, Cong.

Rsch. Serv., R42346, Federal Land Ownership:

Overview and Data (2020) .....................................9

H. Joint Mem’l 9, 68th Leg., 2d Reg. Sess.

(Idaho 2026) .....................................................1, 10

Jason Deforest, The Role of Cooperating Agencies

and Cooperative Federalism in Public Lands

Decisions, 2022 NO. 3 FNREL-INST 10A

(2022) ....................................................................11

John Adams, Discourses on Davila, in 6 Works of

John Adams (C. Adams ed. 1851) .........................8

iv

TABLE OF AUTHORITIES—Continued

Page(s)

John O’Connell, Shoshone-Bannock Tribes plan

to sue to stop Simplot land exchange,

Idaho State J. (Aug. 14, 2020) ...............................4

Lands Potentially Available for Disposal,

Bureau of Land Mgmt. ........................................12

Lewis M. Simes, Public Policy and the Dead Hand

(1955) ......................................................................8

Owyhee Land Exchange, Idaho Dep’t of Lands ..........9

Owyhee Land Exchange, Map of Exchange Acres,

Idaho Dep’t of Lands..............................................9

Policy Resolution 2026-01, Federal-State

Land Exchanges and Conveyances,

W. Governors’ Ass’n (Jan. 2026)..........................10

Southeast Idaho Labor Force And Economic

Profile, Idaho Dep’t of Labor (May 2026) ..............4

Stewart E. Sterk, Restraints on Alienation of

Human Capital, 79 Va. L. Rev. 383 (1993) ...........8

1

INTERESTS OF AMICI CURIAE

Idaho Governor Brad Little and the State of Idaho

through

Attorney

General

Raul

Labrador

(collectively, Idaho) strive to ensure conditions in

which the State’s citizens may flourish.1 Among these

conditions is “the security of Property,” which

Alexander Hamilton described as one of the “great

obj[ects] of Gov[ernment].” 1 The Records of the

Federal Convention of 1787, p. 302 (Max Farrand ed.,

1911). So when a federal court holding threatens to

unsettle ownership of property across potentially

hundreds of thousands of Idaho acres based on an

antiquated statute exhumed from deep within the

United States Statutes at Large, the State is

compelled to speak up.

This is not the first time the State has spoken up

about the decision below, and its opposition has been

echoed by its Legislature, counties, and cities, as well

as by governors from other states, including the

governors of Utah and Nevada who have joined this

brief as amici curiae.2 All have cried out against the

1 Pursuant to Rule 37.6, no counsel for any party authored this

brief in whole or in part and no party or counsel for any party,

other than amici curiae, made a monetary contribution intended

to fund the preparation or submission of this brief. Pursuant to

Rule 37.2, amici curiae provided timely notice of their intent to

file this brief to all parties in this case.

H. Joint Mem’l 9, 68th Leg., 2d Reg. Sess. (Idaho 2026),

https://tinyurl.com/m35ccht8; Amicus Brief of the Governors of

Idaho, Utah, and Nevada, Shoshone-Bannock Tribes of the Fort

Hall Reservation v. U.S. Dep’t of the Interior, Nos. 23-35543, 2325544 (9th Cir. Jan. 24, 2024); Letter from Bannock County

Commissioners to Attorney General of Idaho (Nov. 13, 2025),

2

2

serious effects the decision below portends for Idaho

and its sister states out west.

But the State hopes this is the last time it will be

necessary to speak up against the decision below—

that the Court will grant the petitions for certiorari

filed by J.R. Simplot Company and the Department of

the Interior, correct the Ninth Circuit’s badly flawed

interpretation of the Federal Land Policy and

Management Act (FLPMA) and the 1900 Act,3 and

remove the final obstacle standing in the way of a

land transfer that has been in the works for decades

and promises continued economic security and

increased opportunities for citizens across the Gem

State.

SUMMARY OF THE ARGUMENT

The detrimental impacts of the Ninth Circuit’s

decision are hard to overstate. It not only threatens

the land exchange at issue in this case, which will

result in a massive loss of jobs for hard-working

https://tinyurl.com/7yrb5t7d; Letter from Power County Board of

Commissioners to Governor of Idaho, Attorney General of Idaho,

and Idaho’s Congressional Delegation (Dec. 8, 2025),

https://tinyurl.com/2xjwk2sw; Letter from Caribou County

Board of Commissioners to Governor of Idaho, Attorney General

of Idaho, and Idaho’s Congressional Delegation (Jan. 12, 2026),

https://tinyurl.com/pcz9vscv; Letter from Mark Dahlquist,

Mayor of Pocatello to Governor of Idaho, Attorney General of

Idaho, and Idaho’s Congressional Delegation (Feb. 12, 2026),

https://tinyurl.com/5n85afu7; Letter from the Governors of

Idaho, Nevada, Wyoming, and Utah to U.S. Senate and U.S.

House Leadership (Dec. 2, 2025), https://tinyurl.com/ycxd9p5e.

3 “An Act to ratify an agreement with the Indians of the Fort Hall

Indian Reservation in Idaho, and make appropriations to carry

the same into effect.” Act of June 6, 1900, ch. 813, 31 Stat. 672.

3

residents in the region and thwart economic

expansion that has been anticipated for decades. It

will also unsettle property rights on previously ceded

land, prevent that land from being put to productive

uses in the future, and diminish Idaho’s ability to

participate in and benefit from federal land-use

planning. The Court should grant certiorari and

reverse.

ARGUMENT

The Court should grant Simplot’s and the

Department of the Interior’s petitions for certiorari

“because of the importance of the decision [below] to

the utilization of the public lands.” United States v.

Coleman, 390 U.S. 599, 601 (1968). In particular, the

decision below is of incredible importance to Idaho

because it provokes uncertainty with respect to

previous transfers of federally owned public lands

across large swaths of Idaho and prevents future

transfers of federally owned public lands that would

promote the public interest.

I.

If allowed to stand, the Ninth Circuit’s

decision would significantly harm Idaho.

The

Ninth

Circuit’s

decision

threatens

detrimental consequences for the State of Idaho. The

Court can, and should, prevent those consequences

from ever materializing by granting the petitions for

certiorari and reversing.

A. Idaho will be harmed if the land exchange

at issue in this case is unwound.

For starters, the impact of the Ninth Circuit’s

decision on the proposed land exchange at issue in

this case amounts to a serious blow to the State’s

4

economy. Pocatello is the sixth largest city in Idaho,

Annual Estimates of the Resident Population for

Incorporated Places in Idaho: April 1, 2020 to July 1,

2025 (SUB-IP-EST2025-POP-16), U.S. Census

Bureau,

Population

Division

(May

2026),

https://tinyurl.com/53kmct8y, and Simplot is one of

the city’s largest employers. Southeast Idaho Labor

Force And Economic Profile at 5, Idaho Dep’t of Labor

(May 2026), https://tinyurl.com/4ck32arr. The Don

Plant is directly responsible for more than 600 jobs—

which includes jobs at the plant itself in Pocatello and

jobs at Smoky Canyon Mine in Caribou County,

Idaho, where the plant obtains its phosphate ore—as

well as more than a thousand other jobs that

indirectly rely on the Plant. John O’Connell,

Shoshone-Bannock Tribes plan to sue to stop Simplot

land exchange, Idaho State J. (Aug. 14, 2020),

https://tinyurl.com/37k7tvub.4 The Don Plant’s

operations also bring in significant capital to the

State’s economy.

The land exchange at issue in this case would

have been a boon to the economy of the State and the

region. The BLM projected that the exchange “would

support about 3,763 jobs—generating around $172.7

million in income—and would contribute nearly

$768.3 million a year in industrial activity across the

region.” App. 34a (Bumatay, J. dissenting).

That expected economic benefit may very well

evaporate into thin air—along with the jobs the Don

4 The Don Plant is also responsible for jobs outside of Idaho.

Many of the workers at Smoky Canyon Mine live in Wyoming.

Simplot also has a sister fertilizer operation with a processing

facility in Rock Springs, Wyoming that is connected to a

phosphate mine in Vernal, Utah.

5

Plant currently supports—if the Ninth Circuit’s

decision is not reversed. Simplot has represented that

if it is forced to unwind the land exchange it “will stop

operating once it reaches storage capacity,” which it

“has estimated could occur as soon as 2031.” Simplot

Pet. at 8. The Court can avoid that catastrophe by

granting the petition and properly applying federal

law.

B. Idaho will be harmed by the broader

impact of the Ninth Circuit’s holding.

The dissolution of a project that would create

“$768.3 million a year in industrial activity across the

region” would be bad enough for the State on its own.

App. 34a (Bumatay, J. dissenting). But the

detrimental effects of the decision below are not

limited to one land exchange at one location.

As for the territorial reach of the Ninth Circuit’s

decision in Idaho, it would potentially affect any land

that was ceded by the 1900 Act, Act of June 6, 1900,

ch. 813, 31 Stat. 672—more than 416,000 acres. For

perspective, that includes any federal land in the

yellow shaded region below.5

5 Map showing the current Fort Hall Reservation and previously

held lands of the Shoshone-Bannock tribes in Idaho, Ballotpedia

(Dec. 28, 2015), https://tinyurl.com/4k58ryyt.

6

Other regions of the State are affected as well. An

even larger area in Idaho—originally more than

530,000 acres6—was ceded around the same time

from the Nez Perce reservation near Lewiston, Idaho

See 29 Cong. Rec. 365 (1896) (containing a chart showing

acreage of ceded reservation, listing Nez Perce as ceding 530,000

acres and opening 550,556 acres to settlement and entry).

6

7

(home to Idaho’s only seaport) that contains nearly

identical language to that of the 1900 Act. See Act of

Aug. 15, 1894, ch. 290, § 16, 28 Stat. 286, 332 (land

“shall be subject to disposal only under the

homestead, town-site, stone and timer, and mining

laws”). Three more tracts of land around Coeur

d’Alene, Idaho were conveyed with similar language.

Act of Aug. 15, 1894, ch. 290, § 14, 28 Stat. 286, 323

(“disposed of under the homestead and town-site

laws”); Act of July 13, 1892, ch. 164, 27 Stat. 120, 124

(“subject to entry only under the town-site laws of the

United States”); Act of Mar. 3, 1891, ch. 543, § 22, 26

Stat. 989, 1031 (“disposed of . . . only[ ] under the

provisions of the homestead law . . . and under the law

relative to town sites or to locators or purchasers

under the mineral laws”).

The effect of the Ninth Circuit’s decision across

this territory will be both retrospective and

prospective.

The backward-looking impact is that land

ownership in the previously ceded areas becomes

uncertain. The Ninth Circuit’s decision suggests that

any land exchange or other disposal of land by the

federal government in these regions is invalid,

thereby clouding title to any previously transferred

land. This obviously is incredibly destabilizing—as

this Court has previously acknowledged, there is a

“special need for certainty and predictability where

land titles are concerned.” Leo Sheep Co. v. United

States, 440 U.S. 668, 687–88 (1979). FLPMA’s aim of

creating “uniform procedures for any disposal of

public land” would be undone. 43 U.S.C.

§ 1701(a)(10).

8

The federal government gives an idea of some

Idaho lands that might be affected by the decision.

“Interior reports that, over [the relevant] time, the

government has often conveyed portions of the land,

including for residential development, a Jewish

community center, the expansion of the Bannock

County landfill, and Idaho State University’s flagship

Pocatello campus.” DOI Pet. at 28. Surely there are

more examples, and each destabilized property right

will result in destabilized liberty for Idahoans. John

Adams, Discourses on Davila, in 6 Works of John

Adams 280 (C. Adams ed. 1851) (“[p]roperty must be

secured, or liberty cannot exist”).

The prospective impact of the Ninth Circuit’s

decision is that it leaves the federal government

without “a viable method for disposing of ” land in the

affected regions in Idaho. App. 38a (Bumatay, J.

dissenting). Like any other restraint on alienation,

the inevitable effect is that that the decision below

will render the land’s use “inefficient because [it will]

prevent exchange of [land] to persons who value [the

land] most.” Stewart E. Sterk, Restraints on

Alienation of Human Capital, 79 Va. L. Rev. 383, 428

(1993) (citing Lewis M. Simes, Public Policy and the

Dead Hand 34-35 (1955)). That is precisely the result

that FLPMA sought to avoid. 43 U.S.C. § 1716(a)

(authorizing Secretary to dispose of land when it

serves the “public interest,” which is broadly defined

to include welfare-maximizing considerations).

The principle that restraining the government’s

ability to transfer land will prevent the land from

9

being put to its “most effective use”7 is vividly

illustrated through land exchanges—which may seem

uncommon to those residing east of the Rocky

Mountains, but are not so rare out west.8 Consider a

land exchange that Idaho recently closed. The State

swapped 23,878 acres of its land for 31,030 acres of

BLM land, while paying a $30,000 difference to

equalize the values.9 The exchange enabled both

landowners to block-up previously intermingled

parcels for more efficient management and improved

access.10 Similar exchanges can add value throughout

western states—in fact, the problem of “checkerboard

ownership pattern[s]” that has “complicate[d] land

management, increase[d] costs, and hinder[ed]

economic and ecological decision making” has

prompted the Western Governors’ Association to “call

on Congress to simplify and expedite federal-state

7 Falls City v. Missouri Pac. R. Co., 453 F.2d 771, 773 (8th Cir.

1971).

8 Carol Hardy Vincent & Laura A. Hanson, Cong. Rsch. Serv.,

R42346, Federal Land Ownership: Overview and Data 7–8

(2020), https://tinyurl.com/yck9xejr (listing federal land

ownership by state); see also Idaho Admission Act § 5(c)(3)(B), 26

Stat. 215, as amended by Act of Oct. 27, 1998, Pub. L. No. 105296, § 1, 112 Stat. 2822. (“All land exchanges made with the

United States before the date of the enactment of this paragraph

are approved.”)

Owyhee Land Exchange, Idaho Dep’t of Lands,

https://tinyurl.com/2bbda7yb (last visited Aug. 14, 2026).

9

10 Owyhee Land Exchange, Map of Exchange Acres, Idaho Dep’t

of Lands, https://tinyurl.com/7ekshvxf (last visited Aug. 14,

2026) (showing intermingled ownerships).

10

land exchange, sale, and conveyance processes.”11 The

Ninth Circuit’s decision is a giant leap in the opposite

direction.

It’s not hard to envision other circumstances in

which exchanging land under FLPMA would enable

land to be put to a welfare-maximizing use.

Consolidated blocks of land may be needed for utilityscale energy projects, electricity transmission

development and grid improvement projects, or

housing development.12 Nevada has used land

exchanges to increase the state’s housing stock.13

Idaho may very well wish to pursue a land exchange

with the federal government in the future—it

currently owns at least 9,600 acres of land that was

previously ceded by the 1900 Act.

The Ninth Circuit’s decision, however, means

that the federal government’s current holdings of land

in Idaho on affected ceded regions will be frozen in

amber. And by “severely hamper[ing] the federal

government’s ability to administer its lands,

11 Policy Resolution 2026-01, Federal-State Land Exchanges and

Conveyances,

W.

Governors’

https://tinyurl.com/2fvmh6c9.

Ass’n

(Jan.

2026),

H. Joint Mem’l 9, 68th Leg., 2d Reg. Sess. (Idaho 2026),

https://tinyurl.com/m35ccht8 (“[E]xchanges and other disposal

options are vital tools for administering such lands and

achieving important recreation, community development,

wildlife conservation, and resource development objectives, such

as timber harvesting, mining, and energy projects.”).

12

13 Amy Alonzo, Will the release of federal land help Nevada’s

affordable housing crisis? It depends, The Nev. Indep. (June 1,

2025), https://tinyurl.com/y5r7j2rm; Southern Nevada Public

Land Management Act, Pub. L. 105–263, § 4(a) (October 19,

1998).

11

including its ability to sell or exchange lands,” the

decision has also hamstrung the federal government’s

ability “to promote economic development or sustain

jobs in local communities.” App. 136a (Tung, J.,

dissenting from denial of rehearing en banc).

C. Idaho’s ability to affect and benefit from

federal land policy is diminished by the

Ninth Circuit’s holding.

Idaho’s statutorily granted ability to influence

and benefit from federal land policy is also hampered

by the Ninth Circuit’s decision.

Congress enacted FLPMA during the Sagebrush

Rebellion—a movement in the 1970s and 1980s in the

American West to transfer federal land to states. The

Rebellion “did not lead to a transfer of federal lands,

[but] it did result in a heightened willingness of the

federal government to work with states and an

increased capacity of the states to offer substantive

expertise and clearly articulated policies supported

the rise of this informal, administrative federalism.”

Jason Deforest, The Role of Cooperating Agencies and

Cooperative Federalism in Public Lands Decisions,

2022 NO. 3 FNREL-INST 10A (2022) (cleaned up).

FLPMA accordingly acknowledges “the national

interest will be best realized if the public lands[’]. . .

present and future use is projected through land use

planning process coordinated with other Federal and

State planning efforts.” 43 U.S.C. § 1701(a)(2).

FLPMA expressly invites States’ active

participation in crafting federal land policy to

maximize the use and management of federal lands.

When developing a resource management plan to

establish permissible uses and objectives for different

12

plots of federal land—which may include plans for

disposal or exchange14—the Secretary of the Interior

is required to “coordinate . . . with the land use

planning and management programs . . . of the States

and local governments within which the lands are

located.” 43 U.S.C. § 1712(c)(9). The Secretary must

also “keep apprised of state, local, and tribal land use

plans,” “assure that consideration is given to those”

plans, “assist in resolving” any inconsistencies with

those plans, and provide “meaningful public

involvement of State and local officials.” Id.

Moreover, in deciding whether to exchange a tract

of federal land, the Secretary must determine

whether “the public interest”—which includes “the

needs of State and local people”—“will be well served

by making that exchange.” 43 U.S.C. § 1716(a). The

Secretary must also inform the Governor at least 60days prior to any sale. Id. § 1720.

Pursuant to these statutes, Idaho regulators were

closely involved in the land exchange at issue in this

case. Idaho Department of Fish and Game offered

support for the exchange because it would put

improved winter habitat for mule deer into the public

domain. See S.E. Idaho Mule Deer Foundation’s

Amicus Curiae Brief at 6, Shoshone-Bannock Tribes

of Ft. Hall Reservation v. U.S. Dept. of Int., No. 4:10CV-004-BLW, (D. Idaho May 3, 2011) Dkt. 44. Idaho’s

Department of Environmental Quality also played an

active role since it is the entity that regulates and

processes permits for gypsum stacks. Notice of

Availability for the Final Environmental Impact

Lands Potentially Available for Disposal, Bureau of Land

Mgmt., https://tinyurl.com/3mc7h7mn.

14

13

Statement for the Proposed Blackrock Land

Exchange, 85 Fed. Reg. 31804–02 (May 27, 2020); Ex.

1 to Mem. in Supp. of Plf ’s. Mot. to Enter Consent

Decree at 16–19, United States of America v. J.R.

Simplot Co., No. 1:23-CV-322-DCN (D. Idaho Mar. 21,

2024) Dkt. 11-1.

But now, Idaho’s land use plans and expertise will

be of no consequence to the extent they would counsel

that best management practices would be served by

transferring federal land in the ceded areas. And land

exchanges that the federal government would

undertake in the public interest to serve the needs of

Idaho and its local people will never occur. Indeed,

this land exchange, to which the State’s regulators

committed considerable resources, will never occur—

unless the Court grants the petitions.

CONCLUSION

The petition for a writ of certiorari should be

granted.

14

Respectfully submitted,

RAÚL R. LABRADOR

Attorney General

JOY M. VEGA

Deputy Attorney

General, Chief of

Energy & Natural

Resource Division

ANDREW SNOOK

General Counsel

OFFICE OF GOVERNOR

BRAD LITTLE

MICHAEL A. ZARIAN

Solicitor General

Counsel of Record

IDAHO OFFICE OF THE

ATTORNEY GENERAL

700 W. Jefferson St.

Suite 210

Boise, Idaho 83720

(208) 334-2400

michael.zarian@ag.idaho.gov

Counsel for Amici Curiae

AUGUST 20, 2026

15

AUTHORIZED OFFICERS OF THE AMICI

GOVERNOR JOE LOMBARDO

State of Nevada

Nathan Hastings

General Counsel

GOVERNOR SPENCER J. COX

State of Utah

Jacob Hart

Deputy General Counsel