As Herd Populations Explode, So Does Wyoming’s Wild Mustang Dilemma

Estimates put Wyoming’s wild mustang population at more than double its target prior to winter. BLM officials wait for winterkill numbers.

Mark Heinz

July 08, 20232 min read

Wyoming wild mustangs 6 24 23
(Getty Images)

As of last fall, Wyoming mustangs numbered well over 8,000 — more than twice the state’s target population — but it’s still not clear how many died over the winter. 

Mustang counts late last year estimated 8,828 horses statewide, according to Bureau of Land Management spokesman James Fisher. That’s the number he gave in a written response to inquiries from wild horse advocate Chad Hanson of Casper. Fisher also shared the information with Cowboy State Daily. 

Hanson wrote to the BLM earlier this month questioning a population estimate of 8,181 mustangs. That figure was cited by BLM officials during a recent meeting of the Wyoming Legislature’s Joint Select Federal Natural Resource Management Committee. 

Wyoming’s target mustang population is 3,725, according to the BLM, which is charged with managing the horse herds. 

Some Were Missed In Initial Counts 

Previous mustang counts, which put the mustang population at 4,734, were probably off, Fisher stated. 

Horse numbers might have been underestimated prior to a mustang roundup in 2021, he said. 

“Also, while going through and prioritizing gathers for the state it was noticed the annual population estimates were off by a year. Knowing this now, the population estimates were updated accordingly -- so instead of showing 4,734 horses for 2022, it really should have been closer to 5,680 since we generally expect a 20% growth rate in a typical year,” Fisher stated. 

Counts might also have been off, or foals overlooked in some areas, he added. Factoring in those corrections resulted in the 8,828 estimated mustang population. 

Winter Death Toll Still Unknown 

Fisher acknowledged that the 8,000-plus mustang estimates could very well change, perhaps dramatically, once winterkill is accounted for. 

“It’s important to note that each of these population estimates were made pre-winter and we are still assessing the impact of winter on the wild horse population,” he stated. “We will have a much clearer site picture after we conduct our surveys and counts.”

In some parts of Wyoming, deer and antelope herds suffered devastating losses this winter, but it was thought that mustangs had fared better. 

Hanson and other wild horse advocates told recently Cowboy State Daily that according to what they’ve seen out on the range so far this spring, the mustang herd also suffered mass die-offs

Mark Heinz can be reached at

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Mark Heinz

Outdoors Reporter