As the corral gate opened, wild mares headed for home. Some hesitated to look back at other members of the herd still to be released, or to look at the hay and water they were leaving behind, but each group galloped off in the same direction- back toward the Shawave Mountains.

The mares were marked for life with a “FC” on their left shoulders. The freeze brand shows they were vaccinated twice in 30 days with GonaCon, a fertility control drug. It was the first GonaCon fertility control project in the Bureau of Land Management’s Winnemucca District according to BLM Wild Horse & Burro Specialist Garrett Swisher of the BLM’s the Black Rock Field Office.

Forty-four mares were selected for the project because they were “dry” meaning they did not have nursing foals, Swisher said after the release. The mares were corralled for 30-days at the C Punch Ranch so they could be vaccinated a second time with a booster shot of GonaCon.

“Size, conformation and dry mares, meaning they don’t have any foals on them,” Swisher said. “This is the first time we have administered GonaCon in this district. We will see how the results are with these mares before we make the decision on future GonaCon projects...I think it has promise but we’ll see how it works.”

Good results would be an 80 percent reduction in foals born to vaccinated mares, he said. If the results are acceptable, other wild mares in the Winnemucca District could be vaccinated with GonaCon. Swisher said he was not impressed with PZP, another wild horse fertility control drug.

BLM Wild Horse & Burro Specialist Ben Noyes of the Ely District was on hand to assist with GonaCon booster shots before the mares were released. Noyes said a GonaCon project in his district succeeded in reducing the number of foals born in a small herd of wild horses. But, Noyes said it took a couple of years to know for sure if the drug had done the job. 

“We started in 2015 to see how (GonaCon) would work in the Water Canyon area,” Noyes said. “Fantastic. It doesn’t abort the foal that’s already in the (womb). It’s the following two years where you see the results. Our efficacy rate was around 83 percent (fewer pregnancies) the first year and roughly 65 percent the second year. Those horses have had it three times and we administer it every other year...There’s usually 15 to 20 mares that we give a shot to.” 

In August, 1,653 wild horses and 220 burros were rounded up by helicopter in the Shawave Mountains HMA. Twelve were euthanized, four due to roundup injuries such as broken necks and eight due to pre-existing conditions such as missing eyes or teeth according to the BLM.

The BLM claims excess mustangs and burros are a threat to multiple-use on public land such as livestock grazing and wildlife. The AML (Appropriate Management Level) set by the BLM for the 177,204-acre Shawave Mountains HMA is 82 to 136 wild horses and zero burros. That amounts to 1,303 to 2,161 acres per wild horse, numbers questioned by wild horse advocates.

As for livestock grazing the same land, the 1,376,287-acre Blue Wing-Seven Troughs Grazing Allotment covers five HMAs (including Shawave) and parts of five HAs (Herd Areas). The BLM allows a total of 25,864 Animal Unit Months (14,058 active and 11,806 suspended) for one cattle owner and a total of 6,364 AUMs (6,258 active and 106 suspended) for three sheep operators.


The Shawave Mountains gather was scheduled for 45 to 60 days but took 21 days. Wild Horse Education Founder Laura Leigh said the roundup was “fast tracked” with inhumane treatment of wild horses and burros. The animals were helicopter herded for miles through heavy wildfire smoke and thick dust, conditions that should have delayed the roundup according to Leigh.

“BLM should have postponed the operation until the fire was contained or the wind shifted,” Leigh reported on the WHE website on August 23. “The operation was cleared through September 9. There was absolutely no reason to risk equine, or human, health.”

Swisher claimed helicopter gathers are more efficient and humane than water or bait trapping where trap corrals are set around water or food. Wild horses and burros will not enter the traps until they are “starving” for water or food which causes more stress on the animals, he said.

“The helicopter gather is, in my opinion, less stressful and more humane,” Swisher said.

Shawave horses not released ended up in corrals at the private Indian Lakes Off-Range Holding Facility in Fallon while the burros were sent to the Axtell Holding Facility in Axtell, Utah. The animals should be ready for adoption or sale in two or three months according to the BLM. But, the Fallon facility is closed to the public except during guided tours held twice a year.

John Neill, manager of the BLM’s Palomino Valley Wild Horse & Burro Center, said his vacant corrals are reserved for other roundups and that’s why the Shawave wild horses ended up in Fallon. He didn’t know when or if an Indian Lakes tour would happen this fall due to COVID but said Shawave horses could be on the BLM’s “Online Corral” when they are ready for adoption.

Wild horses not adopted or sold during online auctions are transferred to other adoption facilities or long-term holding facilities outside the state according to Neill. The Palomino Valley facility is also closed to the public but animals can be observed from the perimeter. Neill said anyone interested in adopting a wild horse or burro may call him for more information at 775-475-2222.

BLM Winnemucca District Manager Ester McCullough assisted with GonaCon booster shots for the mares released back to the Shawave Mountains in Pershing County. If the project is a success, more mares could be vaccinated and released during future roundups in the district.

“We definitely want to do fertility control,” McCullough said. “Getting the wild horse numbers down to a manageable level is both good for the land and good for the horses so that they are not having to compete so much for forage, water and over-running the area.”

Leigh said Herd Management Area Plans would be a step forward with long-term management of wild horse and burro herds as well as the land and water. Such plans could result in fewer roundups and less wild horses and burros in long-term holding facilities at taxpayer expense.