The first known contact between the Cahuilla and non-Indians occurred in 1774 when a Spanish expedition led by Juan Bautista de Anza—in search of a trade route from present-day southern Arizona to the San Gabriel Arcangel Mission near present-day Los Angeles—traversed their lands. Since the Cahuilla lived in more isolated desert and mountain regions, they managed to maintain their traditional way of life through the first half of the 19th century, unlike tribes to the west that fell under the influence of Spanish missionaries early on.
In 1849—50, Cooswootna, a Mountain Cahuilla leader known to non-Indians as Juan Antonio, offered support to the U. S. military, helping protect an expedition under Lieutenant Edward Fitzgerald Beale against attacks by the UTE. In appreciation, Beale, presented the Cahuilla chief with a set of military epaulets that he wore as part of his ceremonial clothing. In 1851—52, Cooswootna helped suppress a Cupeno uprising led by Antonio Garra. In spite of Cooswootna’s aid, the California senate refused to ratify an 1852 treaty giving the Cahuilla control of their lands. In 1854—55, Cooswootna himself led attacks on settlers, but when attempts at an alliance with the Yuma and Mojave failed, he ended the resistance. In 1863, Cooswootna died in a smallpox epidemic that ravaged the tribe. (Almost 100 years later, in 1956, in the course of an archaeological excavation at San Timoteo, an Indian skeleton was discovered with military epaulets, which were used to identify it as that of Cooswootna; his remains were reburied with tribal honors.) Starting in 1877, the U. S. government established reservation boundaries that significantly reduced Cahuilla lands. The development of Palm Springs as a resort area led to further cultural dispossession.