After the 1820s, the Maricopa, under relentless pressure from the Yuma and other tribes, and population loss from epidemics, had been compelled to leave the Gila below Gila Bend and join the Pima in the Middle Gila region. By the time of the California Gold Rush the Maricopa villages, were all located east of the Sierra Estrella, on the Gila River, below the Pima Villages.