California and the Indian Wars:

Miwok-Yokut Raids into Mexican California, 1830-1840

by Warren A. Beck and Ynez D. Hasse

The decade the 1830's saw the Mexican Californios everywhere on the defensive. From San Fernando to the Bay Area~missions, ranchos, and towns were subjected to a constant series of Indian attacks, with large numbers of horses and cattle being taken and many people killed and injured. Valley Indians, usually Yokuts but also Miwoks crossed Cholam Pass, Panoche Pass, Pacheco Pass and Tejon Pass along the riverine area to raid almost at will. After 1833, hardly a year passed without reports of such depredations and petitions to the authorities for help. For example, in 1838 several rancheros were killed near Monterey by Indians; in 1839 the grain storehouse at Santa Clara was attacked; and in 1841 Mission San Juan Bautista was under siege. At San Luis Obispo more than a thousand head of stock were lost in a single raid. . . .

http://www.militarymuseum.org/Miwok.html

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