 The Acjachemen lived to the south, and the Tongva to the north, of the southwest-running Aliso Creek that flows to the Pacific in an area southeast of the Santiago Creek watershed.An Acjachemen-Tongva boundary terminated at the Aliso Creek headwaters, but it is uncertain where the boundary was that divided Santiago Creek within the native territories.Archaeological evidence suggests that the upper portions of the creek were settled by Native Americans, and some historical accounts including those of the Spanish settlers, mention the Acjachemen lived in the canyon of upper Santiago Creek.