Sir yn nhalaith Califfornia , Unol Daleithiau America , o 1851 hyd 1874 oedd Klamath County, Califfornia . Tra roedd yn bodoli, symudodd sedd y sir ddwywaith, ac yn y pen draw, cafodd rhannau o'r diriogaeth eu torri i ffwrdd a'u hychwanegu at siroedd cyfagos. Dyma'r unig sir yng Nghaliffornia i gael ei datgysylltu.
Map o leoliad y sir o fewn Califfornia
Lleoliad Califfornia o fewn UDA
Mae sir o’r un enw yn talaith Oregon , sef Klamath County, Oregon .
Siroedd (a phrif drefi) o fewn talaith Califfornia Alameda County , Alpine County , Amador County , Butte County , Calaveras County , Colusa County , Contra Costa County , Del Norte County , El Dorado County , Fresno County , Glenn County , Humboldt County , Imperial County , Inyo County , Kern County , Kings County , Lake County , Lassen County , Los Angeles County , Madera County , Marin County , Mariposa County , Mendocino County , Merced County , Modoc County , Mono County , Monterey County , Napa County , Nevada County , Orange County , Placer County , Plumas County , Riverside County , Sacramento County , San Benito County , San Bernardino County , San Diego County , Sir San Francisco , San Joaquin County , San Luis Obispo County , San Mateo County , Santa Barbara County , Santa Clara County , Santa Cruz County , Shasta County , Sierra County , Siskiyou County , Solano County , Sonoma County , Stanislaus County , Sutter County , Tehama County , Trinity County , Tulare County , Tuolumne County , Ventura County , Yolo County , Yuba County