In an effort to boost watershed health, the Bureau of Land Management (BLM) plans to round up thousands of wild horses that roam a 912,000-acre parcel of public land in Lincoln County, Nevada. It’s part of BLM’s 10-year plan to eliminate all wild horse herds within a 40 mile radius of Caliente, Nevada due to “a decade-old analysis showing too little water and forage to sustain healthy wild horses” within that area, the Las Vegas Review-Journal reports.

However, not everyone agrees with BLM’s plans.

Last week, a lawsuit was filed by Western Watersheds Project, The Cloud Foundation and the American Wild Horse Campaign to stop the massive wild horse removal. The suit alleges that BLM’s move to round up the horses is a violation of the Wild Free-Roaming Horses and Burros Act as well as other federal laws.

“We are directly challenging the BLM’s decision to eradicate all federally protected wild horses from the public lands within the Caliente Complex while continuing to authorize thousands of privately owned cattle to graze the same area,” Bill Eubanks, an attorney representing the groups, said in a written statement.

According to the Las Vegas Review-Journal, BLM’s 2008 resource management plan for the Caliente Complex, which is comprised of nine separate herd areas, cannot “support wild horses on a long-term basis.” With an estimate of over 1,744 wild horses within the complex, BLM says the number of wild horses is unsustainable for the land and incredibly harmful to overall watershed health; however, those suing BLM argue that it’s not the horses that are the problem: it’s the 4,500 domestic cows and sheep.

“We have a real and widespread problem with overgrazing on western public lands, and in almost every case the cause is domestic livestock, not wild horses, or mule deer or elk,” Erik Molvar, executive director of the Western Watersheds Project, told the Las Vegas Review-Journal.

BLM does not comment on pending litigation; however, there has been no start date confirmed for the round-up.