A federal court on Tuesday stopped the Bureau of Land Management from capturing thousands of wild horses, saying the agency failed to explain whether the roundup would maintain a “thriving natural ecological balance” on public land in southwest Wyoming.

The federal 10th Circuit Court of Appeals in Denver returned the case to the U.S. District Court in Wyoming, where Judge Kelly Rankin had sided with the BLM and its several allies, including the state of Wyoming. American Wild Horse Campaign, Animal Welfare Institute, Western Watersheds Project and many others had sued on behalf of the wild horses and their advocates.

The BLM had already postponed the roundup, which was originally scheduled to begin on the cusp of the ruling.

The Wyoming court must now reconsider the case. The appeals court suggested the BLM could again address the conflict between horses, domestic stock and wildlife “in a manner that is designed to achieve and maintain a thriving natural ecological balance on the public lands.”

The BLM had maintained that it did not have to take that “balance” metric into account when it decided on the roundup.

“Since BLM admitted that it did not consider ecological balance, [its] plan failed to consider an important aspect of the [Wild Free-Roaming Horses and Burros Act],” Circuit Judge Timothy Tymkovich wrote for a three-judge appeals panel.

The roundup targeted about 3,600 free-roaming horses across as much as 1.1 million acres between South Pass and the Colorado border. Much of that land is a checkerboard pattern of private and public land ownership.

The Rock Springs Grazing Association, which sided with the BLM in the decades-long dispute, owns much of the private land in the region and leases public property for grazing. Nevertheless, “[p]rivate landowners are prohibited from fencing their land and preventing feral horses or other wildlife from passing through,” the appeals court said.

The appeals court panel found the BLM decision to be arbitrary and capricious. But instead of setting the plan aside, it suggested the BLM could likely mitigate the court’s concerns by offering a fuller explanation of its reasoning.

BLM argument “too clever”

The BLM puts captured horses and burros up for sale or adoption and imposes various safeguards and conditions to ensure they are treated humanely. Slaughter is not allowed.

Wild horse advocates called Tuesday’s ruling “a significant win and a meaningful check on BLM overreach.” The court found that “the BLM cannot sidestep the law to appease special interests and eliminate wild horses from their rightful habitat,” Suzanne Roy, executive director of American Wild Horse Conservation, said in a statement.

A representative of stock and wool growers did not comment Tuesday, saying he had not yet read the opinion.

The appeals court finding centered on the Administrative Procedures Act that requires the BLM to consider important aspects of a problem, among other things. The agency claimed it did not have to consider ecological balance when analyzing the roundup in a plan to manage resources across the region.

Instead, the roundup plan was a “precursor decision” to which the Wild Free-Roaming Horses and Burros Act did not apply, the BLM asserted.

The appeals panel was unconvinced.

“This argument is too clever by half,” Tymkovich wrote. If the BLM’s position prevailed, that “would allow BLM to use the [resource management plan] process to skirt its Wild Horse Act obligations,” the decision states.

In reaching its conclusion, the court dismissed, for now, complaints that the BLM did not follow federal environmental and land-use laws, including that it gave short shrift to the potential of consolidating checkerboard holdings through a land exchange.

The court accepted the BLM explanation that “a land exchange would entail extensive surveys of millions of acres for mineral value, cultural resources, and potential hazardous materials, which would likely take years to complete and demand extensive agency resources.”

(WyoFile is an independent nonprofit news organization focused on Wyoming people, places and policy.)