A Spanish presidio in Sonora about 150 miles south of the present international boder between Arizona and Mexico. It was the capital of Sonora at the time of the Anza Expedition and, thus, the governor of Sonora lived there. Anza and the colonists spent the summer of 1775 there, waiting for the monsoon rains of August to cool temperatures and fill the water holes. The time at Horcasitas was also used to train the newly recruited male colonists in military tactics. (D.G.)