Prior to incorporation in 1850, the area now encompassing San Joaquin County was inhabited by the Yokuts and Miwok native peoples. These communities lived in villages throughout the region, consuming diverse diets that reflected the flora and fauna of the California Delta. Acorns from Valley Oak trees, salmon runs on the San Joaquin, Mokelumne, Calaveras, and Stanislaus rivers, and Tule Elk were staples of the native diet, which was supplemented with various native berries and plants. The native population of San Joaquin County fell dramatically during a state-wide epidemic of malaria in 1828, and a subsequent rebellion of native peoples in the Central Valley, led by Chief Estanislao.