From Wikipedia

The Native Americans

Episode One

The Far West, Generous Spirit

The Population of Native California was reduced by 90% during the 19th century—from over 200,000 in the late 19th century to approximate 15,000 at the end of the century. Epidemics swept through California Indian Country, such as the 1833 malaria epidemic. In 1834 the Spanish missions shifted to Mexican control and were secularized, but lands under their control were not reverted to tribes. Many landless Indians found wage labor on ranches. The United States took control of California in 1848 with the signing of the Treaty of Guadalupe Hidalgo, that did not honor aboriginal land title.

Indigenous tribal and languages regions of California.