A group of equine advocates in Louisiana have filed a federal lawsuit to halt the Army’s plan to remove estray horses that roam property at Fort Polk, in Vernon Parish, Louisiana, and the Kisatchie National Forest, which spans seven central and northern Louisiana parishes.

Last year, the Army issued a public notice of intend to conduct an environmental assessment in advance of a proposed action to remove the so-called “trespass horses” at Fort Polk. In April the Army released the final assessment, which stated that, due to herd growth, the horses interfered with Army training operations at the base and in the national forest and presented a safety concern to nearby communities.

On Dec. 14, the Pegasus Equine Guardian Association (PEGA) filed a lawsuit asking the court to prevent the Army from removing the horses on grounds that the animals had roamed the base and national forest property since the 1600s, and that the removal plan threatens the horses’ long-term survival.