Yuma Crossing
Immediately after the Mexican–American War in 1848, the U.S. Army built Fort Yuma here to protect travelers from Indians raiding the area. It was the center point of conflict in the Yuma War of 1850–53. From 1864–1890, the fort and nearby facilities was the main army base to support the US Army's efforts to control the Indians throughout the greater southwest.
Yuma War
Later the Yumans came into conflict with the Maricopas, and in 1857 the last major battle involving the Yuma was fought. In an engagement at Pima Butte in the Sierra Estrella Mountains, the Maricopas and Pimas defeated and killed well over 100 Yumans and their allies. After which the Yuma were no longer a military power.