The vast majority of free-roaming horses occupying a vast swath of Wyoming’s Red Desert could be rounded up and trailered away to long-term pastures if Bureau of Land Management plans now being reviewed come to pass.
Potential roundups could target thousands of animals in the Green Mountain, Stewart Creek, Antelope Hills, Crooks Mountain and Lost Creek herds, which dwell on approximately 753,000 acres north of Interstate 80. Collectively known as the “Red Desert complex,” the herds are separate from three other herds roaming the public-private “checkboard” portion of the Red Desert. BLM has long sought to entirely remove the three herds in the checkerboard but that plan is tied up in litigation and on hold until at least October.
Instead of eliminating the Red Desert complex herds, the BLM seeks to knock down numbers to an “appropriate management level” to balance the “the needs of wildlife, livestock, recreation and the long‑term health of the range,” an agency spokesperson told WyoFile in an emailed statement. BLM personnel declined a verbal interview for this story.
Documents accompanying BLM’s proposal contend that the nonnative free-roaming horses have impacted the Red Desert’s ecological health.
“Rangeland resources within the complex have experienced adverse effects as a result of wild horse overpopulation,” states the evaluation report for the Stewart and Lost Creek herds. “Monitoring data specific to this area indicated that past excessive wild horse populations were linked to historical riparian degradation.”
University of Wyoming-led research that included three of the at-issue herds — Crooks Mountain, Green Mountain and Stewart Creek — shows that overpopulated horses are correlated with declining juvenile sage grouse survival rates.
The Red Desert complex herds are overpopulated, at least based on the “appropriate management levels” established in the early 1990s. The goal is for the herds to include somewhere between 480 and 724 total animals, but as of early March the population was estimated at 1,970 horses and expected to grow to 2,300 by the time the herds are surveyed in the fall.
Free-roaming horses face little natural predation and have high survival rates. The herds can grow by about 20% annually — a clip that enables them to double every five years or so. Data included in the evaluation report for the Green Mountain, Antelope Hills and Crooks Mountain herds shows that the Red Desert complex populations have largely followed that trend. Roundups in 2018 and 2020 knocked numbers in those three herds down to about 900 in 2021. By 2027, however, projections are for more than double that many horses.
BLM is in the early “scoping” phase of its plans, and federal land managers have not divulged what exactly they’re proposing. The public notice only states that herd evaluations are more than 30 years old, need to be revised, and the agency’s Lander and Rawlins field offices “intend to gather excess wild horses” from the herds. Presumably, the roundups could target between 1,576 and 1,820 horses, which is the gap between the “appropriate management level” and the estimated fall 2026 population.
Herd plan updates will address the “appropriate management levels,” rangeland health, population suppression methods, genetic diversity and sage grouse habitat, according to the evaluation reports.
Roundups to reduce wild horse numbers from public lands are routine business. This fiscal year, BLM is planning to gather up and trailer away more than 15,000 animals, according to the agency’s most recent gather and fertility control schedule. Planned activities in Wyoming are minimal: They include fertility control on 95 horses in the Stewart Creek and McCullough Peaks herds, and a “drive trap” roundup targeting removal of 286 animals from the Fifteenmile Herd.
The rounded-up equines cannot be intentionally killed because of protections afforded by the Wild Free-Roaming Horses and Burros Act. Some horses find new homes through adoption programs, but most mustangs live out their days at private and government-run pastures, corrals and holding facilities.
BLM is accepting public comment on its proposal through May 4. To submit remarks go to eplanning.blm.gov and search for “DOI-BLM-WY-R050-2026-0012-EA.”
Wild horse advocates are encouraging the public to get involved. Carol Walker, writing in her Wild Hoofbeats blog, urged the BLM to consider restoring an old herd — Arapahoe Creek — that’s now managed for zero horses right in the middle of where the five existing herds roam.
“It should be changed back to a Herd Management Area, recognizing that it is central to all the HMAs and an integral part of the Complex,” Walker wrote.
