 The California Gold Rush in the mid @-@ 19th century dramatically increased travel by European @-@ Americans in the area , causing competition for resources between the regional Paiute and Miwok and the miners and hangers on . In 1851 as part of the Mariposa Wars intended to suppress Native American resistance , United States Army Major Jim Savage led the Mariposa Battalion into the west end of Yosemite Valley . He was pursuing forces of around 200 Ahwahneechee led by Chief Tenaya . 
