In May 1859, Maj. Carleton and K Company of the 1st Dragoons out of Fort Tejon, California, were detailed to escort Maj. Henry Prince, a paymaster with government funds, to the Southern Utah Territory.

Assistant Surgeon Charles Brewer of the Santa Clara Expedition was in charge of a burial detail that had interred the remains of 39 in three mass graves a few days before the arrival of K Company.

[5] After investigating the incident, Carleton felt his findings were significant enough to deliver as a special report[6] to Maj. W. W. Mackall, Assistant Adjutant-General, U.S.A., San Francisco, California.

Carleton concluded that Mormons, some dressed as Indians, and assisted by Paiute tribesmen, had murdered and plundered the possessions of 120 men, women, and children of a California-bound emigrant train.

As a result, he established Fort Bowie near Apache Pass to guard this critical place on the road between the Colorado and Rio Grande Rivers.

In October 1862, Carleton established Fort Sumner to house captured Mescalero Apache, despite warnings of its unsuitability for a large human presence.

Mangas Coloradas arrived under a white flag of truce to meet with Colonel Joseph Rodman West, an officer of the California Volunteers.

Against the "great evil" of Navajo raiders he began scorched earth tactics, stating they "must be whipped and fear us before they will cease killing and robbing the people.

[10] Carleton used Fort Sumner, which already held many Mescalero Apaches, to house the Navajos, despite warnings of its unsuitability for such a large human presence.

[8] Carleton next sent Carson on an expedition to rid the southwest of raids by Comanche and their Kiowa allies, which resulted in the Battle of Adobe Walls.

Partly on the strength of The Battle of Buena Vista Carleton received an appointment from Secretary of War Jefferson Davis in 1856 to make a study of European cavalry tactics.

Carleton died January 7, 1873, aged 59, in San Antonio, Texas, serving with the 4th Cavalry Regiment in his permanent rank of lieutenant colonel.