Arizona's iconic Salt River horses could soon be a thing of the past: the United States Department of Agriculture Forest Service says it intends to remove approximately 500 wild horses from the grounds of Tonto National Forest.

In a notice published in the Arizona Capitol Times, the agency announced that it will impound all "unauthorized livestock" found in the park beginning Friday, August 7. The Arizona Department of Agriculture will then attempt to auction off all unclaimed animals. Horses that cannot be sold will ultimately be "condemned and destroyed, or otherwise disposed of."

"It just boils down to a safety concern for the Forest Service. We have horses out there on Forest Service land and we have no authority to manage horses and this is how they're proceeding to remedy the safety issue," Tonto National Forest Spokesperson Chandler Mundy told local news station KNXV.

The horse's legal status is, at best, murky. Local news station 12 News reportedthat the population of horses was never assigned a "wild horse territory" and therefore isn't protected under federal law.

Conservationists have been working to prevent the removal. The Salt River Wild Horse Management Group presented the Forest Service with a 50-page "humane management proposal" that the group claims the Service rejected.

"We're very upset that the Forest Service has chosen not to work with us," Simone Netherlands, president of the Salt River Wild Horse Management Group, told KPHO. "We've offered humane solutions [to manage the horse population] at no cost to the Forest Service."

"It's so indicative, we believe, of mankind and our government to just say, 'Let's manage this into extinction,'" Netherlands added.

According to newspaper records, the horses have inhabited the Salt River area since 1890. Unconfirmed reports indicate that they could date back to the 17th century. The population has dwindled from nearly 500,000 in 1927 to approximately 500 today.