After Roberts reached the San Pedro River, it became necessary to learn whether Dragoon Springs, 28 miles further east, could supply both companies with water or whether they would be forced to separate into smaller detachments. Capt. Roberts led the advance detachment with his infantry company, joined by three wagons, the howitzers and seven of Cremony's best horsemen to serve as scouts and couriers. Capt. Cremony remained behind with 15 cavalrymen and ten of Roberts' infantrymen, including the detachment left as a garrison at the river, where an adobe stage station building provided shelter and a defensive position to guard the remaining wagons and animals.