Cassons or Casson is the name of a Yokut Native American tribe in central eastern California. The Cassons are also called the Gashowu. The Casson Yokut territory extended from the eastern side of San Joaquin Valley floor eastward to the upper foothills, between the San Joaquin River to the north and Kings River to south. The Cassons signed the Camp BarbourTreaty under Tom-quit , on the San Joaquin River, state of California, April 19, 1851. The treaty was signed by several Yokut tribes and between Redick McKee, George W. Barbour, and O. M. Wozencraft, commissioners on the part of the United States of America. Casson Yokut territory included Madera County and parts of Fresno County. The three chiefs who signed for the Cassons were Domingo Perez, Tom-mas and Jose Antonio. Many Native Californians had acquired Spanish names during the Mission Period. The Cassons, like other Yokuts, and central California Native groups, were pushed from their homes in the San Joaquin Valley to reservations after they signed several treaties, including the Camp Babour Treaty. The Barbour Treaty, Fremont Treaty and other California treaties were never ratified. Several Casson Yokut families went to work for Yosemite in the early 1900s. Like the surrounding tribes, the MonoPaiutes and the Miwoks, they resided there half year and returned to their tribal areas. Later in the late 1920s, Yosemite National Park built homes for their Native American workers.
Gashowu (Casson) Ethnography The site also includes the neighboring Western Monos. Western Monos were located eastward of the Cassons Yokuts in the high Sierra Nevada and are part of the Uto-Aztecan Numic people.