 Many Plains Miwoks moved back to their home areas, where between 1839 and 1841 John Sutter played the local groups off against one another in order to gain control of the lower Sacramento Valley.Other Plains Miwok families remained in the San Francisco Bay area, intermarried with Ohlone, Patwin, and Yokuts peoples, and found work on local Mexican ranchos.The Northern Miwok inhabited the upper watersheds of the Mokelumne River and the Calaveras River.