The Arizona Guards was a Confederate militia company raised on 18 July 1861 in Pinos Altos, located today in New Mexico but then in Confederate Arizona, at the order of Arizona Governor John Baylor. The unit was commanded by Captain Thomas J. Mastin until 7 October 1861 when he died of sepsis, being replaced by Lieutenant Thomas "Tom" Jefferson Helm. The guards mostly scouted and engaged the Apache, pursuing as far as Lake Guzmán, Mexico. Most of the Arizona Guards were settlers and miners from around Pinos Altos and the Mimbres River valley or other parts of southern New Mexico Territory. Some members of the Guards, alongside the Arizona Rangers of Mesilla later joined the Company A, Arizona Rangers. All three were part of Herbert's Battalion, Arizona Cavalry, until May 1863 when they had been depleted by losses. The Rangers of Mesilla and Guards were disbanded, their men being brought into Company A, which remained in action as the "Arizona Scout Company" until the end of the civil war. As both Herbert's Battalion and the Arizona Scout Company, it was attached to the Army of New Mexico.