In October 1879, Grierson received word that a war party of Ojo Caliente and Mescalero Apache under Chief Victorio entered the Trans-Pecos. He left Fort Concho on March 23, 1880 at the head of five companies of the 10th Cavalry and some of the 25th Infantry to disarm the Mescaleros of the Fort Stanton reservation. Grierson's soldiers fought with Apache raiders over early April, then reached Fort Stanton on April 12. The disarmament was delayed until April 16 because of rains, and resulted in failure when the Mescalero Apache escaped with most of their arms. Grierson returned to Fort Concho on May 16, but left the 10th Cavalry's M Company at the head of the North Concho in case the Apache appeared in the area.