Agua Caliente in southwestern Arizona grew around hot springs long used by Indigenous people and recorded by Spanish missionaries in the eighteenth century. Near the Gila River, it became an important watering place and stop on desert travel routes, later serving stage travel and early ranching and farming. During the Civil War era, nearby ranches and stations linked the area to regional conflict and overland movement. By the late nineteenth century, the springs supported a resort that later drew highway tourists, though the community remained small. Today, ruined buildings and the dried springs reflect how this desert water source once sustained travel, agriculture, and leisure.