Area code 209 is the California telephone area code that was split from area code 916 on October 26, 1957. It covers Stockton, Modesto, Turlock, Merced, Winton, Atwater, Livingston, Manteca, Ripon, Tracy, Lodi, Galt, Sonora, Los Banos, San Andreas, Mariposa, and Yosemite, as well as the northern San Joaquin Valley (part of California's Central Valley) and the Sierra Foothills.