The following codes are used for the counties in the file names of the Statewide Database's 2010 Redistricting Data files. county code county name 1 Alameda County 2 Alpine County 3 Amador County 4 Butte County 5 Calaveras County 6 Colusa County 7 Contra Costa County 8 Del Norte County 9 El Dorado County  10 Fresno County 11 Glenn County 12 Humboldt County 13 Imperial County 14 Inyo County  15 Kern County 16 Kings County 17 Lake County 18 Lassen County 19 Los Angeles County 20 Madera County 21 Marin County 22 Mariposa County 23 Mendocino County 24 Merced County 25 Modoc County 26 Mono County 27 Monterey County 28 Napa County 29 Nevada County 30 Orange County 31 Placer County 32 Plumas County 33 Riverside County 34 Sacramento County 35 San Benito County 36 San Bernardino County 37 San Diego County 38 San Francisco County 39 San Joaquin County 40 San Luis Obispo County 41 San Mateo County 42 Santa Barbara County 43 Santa Clara County 44 Santa Cruz County 45 Shasta County 46 Sierra County 47 Siskiyou County 48 Solano County 49 Sonoma County 50 Stanislaus County 51 Sutter County 52 Tehama County 53 Trinity County 54 Tulare County 55 Tuolumne County 56 Ventura County 57 Yolo County 58 Yuba County