No “Step Zero” Escape Hatch: Tenth Circuit Requires BLM to Address Wild Horse Act’s Ecological-Balance Duty When Amending RMPs

Introduction

In Friends of Animals v. Raby, the U.S. Court of Appeals for the Tenth Circuit confronted a long-running management problem on Wyoming’s “checkerboard” lands—interlaced public and private square-mile parcels that complicate management of wild horses protected by the Wild Free-Roaming Horses and Burros Act of 1971 (the Wild Horse Act). The Bureau of Land Management (BLM) amended its Resource Management Plans (RMPs) in 2022 to reconfigure three Herd Management Areas (HMAs), effectively “zeroing out” two HMAs (Great Divide Basin and Salt Wells Creek) and splitting a third (Adobe Town), citing the impracticality of managing herds without private landowner consent within the checkerboard.

Three coalitions of petitioners—wild horse advocacy organizations and individuals—challenged those amendments, alleging violations of the Wild Horse Act, the National Environmental Policy Act (NEPA), and the Federal Land Policy and Management Act (FLPMA). The district court upheld BLM’s action. On appeal, the Tenth Circuit reversed and remanded, holding that—even at the planning stage—BLM must grapple with the Wild Horse Act’s central command to manage for a “thriving natural ecological balance” (TNEB). The court rejected the NEPA and FLPMA claims but found BLM’s failure to address TNEB rendered its RMP amendments arbitrary and capricious under the Administrative Procedure Act (APA).

Summary of the Opinion

Holding: BLM violated the APA by failing to consider the Wild Horse Act’s TNEB requirement when amending RMPs to reconfigure HMAs. The decision is reversed and remanded to the district court to determine the remedy under the Allied-Signal factors (vacatur vs. remand without vacatur).
Wild Horse Act: The court harmonized the Act with FLPMA’s multiple-use mandate. While wild horses need not be prioritized over other uses, BLM still must manage them “in a manner designed to achieve and maintain a thriving natural ecological balance.” That obligation applies at the planning stage; BLM cannot evade § 3(a) by labeling RMP amendments a “Step Zero” decision.
NEPA: Petitioners’ procedural claims failed. The court found no unlawful predetermination, accepted BLM’s explanation for not developing a “land swap” alternative as infeasible, and held that any effects from potential increased livestock grazing are a “separate project” not required to be analyzed at this stage under the Supreme Court’s 2025 Seven County decision.
FLPMA: The record showed BLM balanced multiple uses and did not cause “undue degradation.” Removing or reducing wild horse populations is not per se degradation under FLPMA.
Remedy: The panel sent the vacatur question back to the district court to apply the Allied-Signal test, noting there is a “serious possibility” BLM might substantiate its decision on remand if it addresses TNEB given changed on-the-ground conditions in the checkerboard.

Background and Context

BLM historically managed these herds across checkerboard lands with consent from private landowners, notably the Rock Springs Grazing Association (RSGA). After RSGA withdrew consent in 2010, litigation proliferated. The Tenth Circuit’s earlier decision in American Wild Horse Preservation Campaign v. Jewell (2016) invalidated a BLM gather that removed horses from public lands based on private-land constraints, emphasizing BLM cannot abandon § 3 protections because of § 4’s private land removal duty. Responding to Jewell’s suggestion that BLM consider amending HMA boundaries, BLM undertook the 2022 RMP amendments now at issue.

In those amendments, BLM:

Converted Great Divide Basin and Salt Wells Creek from HMAs (actively managed for horses) to HAs (areas recognized from 1971 but not actively managed for horses), setting appropriate management levels (AMLs) to zero.
Split Adobe Town: retaining a southern HMA with an AML of 259–536 horses, but reverting the checkerboard-heavy northwest to HA status with AML zero. A boundary fence there limits straying.

Detailed Analysis

Standard of Review and Post–Loper Bright Framing

Proceeding under the APA, the court recited the arbitrary-and-capricious standard, focusing on whether the agency “entirely failed to consider an important aspect of the problem” or “failed to base its decision on consideration of the relevant factors.” Framing the analysis through the Supreme Court’s 2024 decision in Loper Bright Enterprises v. Raimondo, the court began with the threshold question: “Does the statute authorize the challenged agency action?” That framing underscores a post–Chevron landscape where statutory authorization is put front and center, instructing courts to assess the statutory text and structure before deferring to agency views.

The Wild Horse Act, FLPMA, and the “Step Zero” Argument

Harmonizing WHA and FLPMA: FLPMA requires BLM to manage public lands under “multiple use and sustained yield.” The Wild Horse Act, as amended in 1978, commands management “as components of the public lands” and directs BLM to manage in a manner “designed to achieve and maintain” TNEB. The court agreed wild horses are not elevated above other uses (citing New Mexico ex rel. Richardson v. BLM and D.C. Circuit’s American Horse Protection Association v. Watt), but emphasized that the TNEB mandate remains the touchstone for wild horse management decisions.
“Step Zero” rejected: BLM argued that RMP amendments deciding where to manage horses are a preliminary “Step Zero” not subject to the Wild Horse Act’s TNEB duty. The court called this “too clever by half,” holding that choosing where to manage wild horses is itself a “management” decision; at that planning stage BLM must at least explain how its choices comport with, and do not undermine, TNEB.
Dictionary support: The panel used ordinary and legal dictionary definitions to show that “manage” includes decisions about where and how to exercise supervisory direction—reinforcing that RMP reconfigurations implicate § 3(a).
Failure to consider TNEB: BLM conceded at argument—and the EIS/ROD stated—that it did not analyze whether the amendments maintain TNEB. That omission rendered the action arbitrary and capricious for failing to consider an important statutory factor.
Ripeness: Petitioners also argued that “zeroing out” AMLs is tantamount to removal requiring § 3(b) “excess” findings. The court held those removal claims are unripe under Ohio Forestry; any gathers will require separate, site-specific decisions (and NEPA), which can be challenged then.

NEPA: Procedure, Not Outcomes—And Heavy Deference

No predetermination: Petitioners claimed BLM predecided the outcome to satisfy RSGA. The court, applying Forest Guardians, found no “irreversible and irretrievable commitment” prior to the EIS and noted BLM’s broad purpose-and-need statement and consideration of a no-action alternative and other management configurations.
Land swaps as alternatives: BLM explained land exchanges lacked willing parties and would require massive, costly surveys across millions of acres, rendering the option infeasible within planning timelines. The court—invoking the Supreme Court’s Seven County decision’s admonition that courts are “at their most deferential” on EIS breadth and feasibility—found the dismissal reasonable.
Potential increased grazing impacts: Citing Seven County’s “separate project” rule, the court held NEPA does not compel analysis of effects from future, distinct decisions (e.g., allocating forage to livestock) that would themselves require their own NEPA processes. Although foreseeable, those effects are not effects “of the action” at this programmatic stage.

FLPMA: Multiple Use and “Undue Degradation”

Multiple-use balancing: The record reflected BLM weighed impacts on wildlife, soils, vegetation, recreation, and livestock, and sought to maintain at least one managed herd (southern Adobe Town) while addressing checkerboard constraints. The panel held that FLPMA does not require prioritizing wild horses over other uses.
Undue degradation: Petitioners argued removing horses is itself undue degradation. The court rejected that view, noting wild horses are one component among many. BLM reasonably concluded reductions would produce positive effects for other resource values.

Remedy: Allied-Signal Discretion on Vacatur

The APA presumptively calls for setting aside unlawful actions, but the Tenth Circuit remanded the remedy question to the district court to apply the Allied-Signal factors:

Seriousness of deficiencies: The omission is significant—ignoring TNEB—but the court noted a “serious possibility” BLM can substantiate its choices on remand given the checkerboard’s realities and the withdrawal of private landowner consent.
Disruptive consequences: The district court should assess the practical impacts of vacatur on ongoing management and whether remand without vacatur is appropriate.

Precedents Cited and Their Influence

American Wild Horse Preservation Campaign v. Jewell (10th Cir. 2016): Held BLM cannot use § 4 (private land removal) to sidestep § 3 duties for public lands. Suggested amending HMAs might be a better path. This case implements that suggestion while clarifying BLM must still address TNEB at the planning stage.
American Horse Protection Ass’n v. Watt (D.C. Cir. 1982): Recognized 1978 amendments aligned the Wild Horse Act with FLPMA’s multiple-use framework. The panel adopts that harmonizing approach while preserving TNEB as a controlling statutory factor.
New Mexico ex rel. Richardson v. BLM (10th Cir. 2009): Emphasized multiple use does not prioritize any single use. The court draws on Richardson to reject petitioners’ view that wild horses must be favored over other uses, even as it enforces TNEB.
Norton v. SUWA (2004): Clarified RMPs guide future actions; relied upon for the planning context while rejecting BLM’s claim that planning is beyond the Wild Horse Act’s management duties.
Loper Bright Enterprises v. Raimondo (2024): Framed the statutory-authorization question, signaling reduced deference and tighter statutory fidelity when agencies define their own authority.
Forest Guardians v. U.S. FWS (10th Cir. 2010): High bar for NEPA predetermination; applied to uphold BLM’s process.
Ass’ns Working for Aurora’s Residential Env’t (AWARE) v. CDOT (10th Cir. 1998) and Baltimore Gas & Electric v. NRDC (1983): Informed the “rigorous exploration of reasonable alternatives” standard and NEPA’s deference on technical judgments.
Seven County Infrastructure Coalition v. Eagle County (U.S. 2025): Stressed deference in NEPA review; held separate projects’ effects need not be analyzed—a key basis for rejecting the increased grazing claim.
Ohio Forestry Ass’n v. Sierra Club (1998): Guided the ripeness analysis; challenges to future gathers are premature at the RMP stage.
Diné Citizens Against Ruining Our Environment v. Haaland (10th Cir. 2023) and Allied-Signal v. NRC (D.C. Cir. 1993): Provided the remedial framework for determining vacatur versus remand without vacatur.
Iron Bar Holdings, LLC v. Cape (10th Cir. 2025): Described the checkerboard land pattern.
U.S. ex rel. Bergen v. Lawrence (10th Cir. 1988): Referenced for constraints on fencing that would block wildlife/feral horses in the checkerboard context.

Legal Reasoning: How the Court Reached Its Decision

Textual anchor—§ 3(a): The court foregrounded the statute’s mandate to manage wild horses in a manner designed to achieve and maintain a thriving natural ecological balance. That mandate is not confined to gather decisions; it applies whenever BLM “manages,” including when it decides where horses will be managed through RMPs.
Rejecting categorical carve-outs: BLM’s attempt to insulate planning choices from § 3(a) scrutiny failed. The court reasoned that drawing HMA/HA lines is dispositive of where horses may be kept and in what numbers. That is a core management decision that must be reconciled with TNEB.
Harmonization, not hierarchy: The court harmonized WHA and FLPMA: multiple-use balancing remains intact, but TNEB is a statutory constraint and a factor that must be considered. Petitioner’s view (horses must be favored) and BLM’s view (WHA does not reach planning) were both rejected as overstatements.
Record concession: The EIS and ROD expressly disclaimed any TNEB analysis. That admission drove the APA holding: failure to consider an important aspect of the statutory scheme is arbitrary and capricious.
NEPA and FLPMA holdings reinforce, but do not undermine, the WHA ruling: NEPA’s deference and FLPMA’s multiple-use balancing remain robust. The case stands, however, for the independent proposition that agencies must engage with specific statutory purposes (here, TNEB) even when their overall planning complies with other statutes.

Impact and Practical Implications

Planning-stage discipline for BLM nationwide: Whenever RMPs or plan amendments affect wild horse management (HMA designations, boundary changes, AML determinations), BLM must:
- Explicitly consider whether choices are “designed to achieve and maintain” TNEB;
- Explain how multiple-use balancing comports with that mandate;
- Avoid EIS/ROD disclaimers that TNEB is irrelevant at the planning stage.
Wyoming checkerboard and beyond: The opinion recognizes pragmatic constraints in checkerboard landscapes and leaves room for BLM to justify similar plan configurations if it connects the dots to TNEB on remand. Agencies managing mixed-ownership mosaics elsewhere (e.g., Nevada, Utah) should expect similar scrutiny.
Post–Loper Bright statutory grounding: The court’s turn to Loper Bright suggests a trend: agencies must demonstrate that the statutes they administer authorize their specific moves and that they considered the statute’s operative commands. This may invite more focused statutory arguments in future challenges to land-use planning.
NEPA scope confirmed; “separate project” doctrine strengthened: Seven County’s rule limits opponents from forcing programmatic EISs to model downstream effects of distinct, later decisions (e.g., increased grazing). Expect agencies to rely on this when segmenting programmatic and site-specific reviews.
Remedy uncertainty: The district court will decide whether to vacate the RMP amendments pending BLM’s TNEB analysis. This creates strategic considerations for both sides:
- Petitioners will argue the omission is serious and that vacatur is minimally disruptive;
- BLM and intervenors will emphasize disruption and the likelihood that a limited remand can cure the defect.
Litigation pathways: Challenges to specific gathers remain available and ripe when issued. Petitioners should reserve their § 3(b) “excess” arguments for those subsequent decisions.

Complex Concepts Simplified

HMA vs. HA:
- Herd Management Area (HMA): An area BLM actively manages for wild horses; BLM sets an AML (population target range) here.
- Herd Area (HA): An area where horses roamed in 1971 but not actively managed for them now; AML is effectively zero.
Thriving Natural Ecological Balance (TNEB): The Wild Horse Act’s core goal: manage horses to maintain healthy, sustainable ecosystems. It does not require maximizing horse numbers; it requires ecological balance in the mix of resources and uses.
FLPMA “multiple use”: A directive to balance diverse uses—wildlife, recreation, grazing, minerals, etc.—without prioritizing any single use in all places. Agencies must justify trade-offs.
NEPA “hard look” and predetermination: NEPA requires agencies to take a careful, good-faith look at environmental impacts and alternatives. Predetermination exists only if the agency commits to an outcome before completing the EIS.
“Separate project” rule (NEPA): Agencies need not analyze effects that would occur only if a future, distinct decision is made (e.g., increasing livestock AUMs later). Those effects are analyzed in the later decision’s NEPA process.
APA arbitrary and capricious: A court sets aside agency action if the agency ignored a key factor, contradicted the record, or made a clear error in judgment. Here, ignoring TNEB was the key defect.
Allied-Signal remedy test: Courts deciding whether to vacate an unlawful action consider (1) the seriousness of the defect and (2) the disruptive consequences of vacatur. Remand without vacatur is possible where the defect may be cured and vacatur would be unduly disruptive.
Ripeness (Ohio Forestry): Programmatic plans are often not the right moment to challenge site-specific actions; litigants must wait until the agency issues a specific gather/removal decision.

Key Takeaways

BLM cannot use RMP amendments to avoid the Wild Horse Act’s TNEB mandate. Planning decisions that determine where and how horses are managed must address § 3(a).
Wild horses are a component of multiple use, not a trump card; but TNEB is a statutory constraint that must be expressly considered.
NEPA claims failed: no unlawful predetermination; land swaps were reasonably excluded as infeasible; increased grazing impacts are a separate-project issue under Seven County.
FLPMA claims failed: the record showed multiple-use balancing; removing horses is not per se undue degradation.
Remedy is open: the district court will apply Allied-Signal to decide vacatur. BLM may be able to substantiate similar outcomes on remand if it squarely addresses TNEB.

Conclusion

Friends of Animals v. Raby clarifies a vital point in wild horse jurisprudence: BLM’s duty to manage for a “thriving natural ecological balance” is not limited to gathers or removals. It attaches at the planning stage whenever BLM redraws the map of where herds may live or sets AMLs that shape the program. The decision carefully harmonizes the Wild Horse Act with FLPMA’s multiple-use regime—rejecting both a horse-first and a horse-optional framing—and underscores the post–Loper Bright imperative that agencies show their work under the governing statutes.

At the same time, the court reaffirms NEPA’s procedural nature and high deference, and it resists converting FLPMA into a prioritization requirement. The immediate consequence is a remand for BLM to explain how its HMA/HA reconfigurations comport with TNEB in the checkerboard context. The broader legacy is a planning-stage discipline likely to reverberate across BLM jurisdictions: when RMPs reshape wild horse management, an express, reasoned TNEB analysis is no longer optional—it is legally required.