California County Map Formation by Year
1850
1851
1852
1853
1854
1855
1856
1857
1859
1860
1861
1863
1864
1866
1868
1870
1872
1874
1875
1876
1878
1881
1885
1887
1889
1891
1893
1897
1907
1909
1913
1917
1919
1925
California County Map Abbreviations
unorg. = unorganized
g. = gained
w. = with
fr. = from
atmt. = attachment
exch = exchanged
nca.= non county area
ch. = changed
Ala -
Alameda
Alp -
Alpine
Am -
Amador
But -
Butte
Ca -
Calaveras
CC -
Contra Costa
Col -
Colusa
Cos -
Coso
Csi -
Colusa
DN -
Del Norte
ED -
El Dorado
Fr -
Fresno
Gl -
Glenn
Hu -
Humboldt
Im -
Imperial
In -
Inyo
Ke -
Kern
Ki -
Kings
Kl -
Klamath
LA -
Los Angeles
Lak -
Lake
Las -
Lassen
Mad -
Madera
Men -
Mendocino
Mer -
Merced
Mno -
Mono
Mnt -
Monterey
Mod -
Modoc
Mrn -
Marin
Mrs -
Mariposa
Na -
Napa
Ne -
Nevada
Or -
Orange
Pa -
Pautah
Pla -
Placer
Plu -
Plumas
Ri -
Riverside
Sac -
Sacramento
SBr -
San Bernardino
SBt -
San Benito
SCl -
Santa Clara
Scr -
Santa Cruz
SD -
San Diego
SF -
San Francisco
Sh -
Shasta
Sie -
Sierra
Sis -
Siskiyou
SJ -
San Joaquin
SLO -
San Luis Obispo
SM -
San Mateo
Sol -
Solano
Son -
Sonoma
St -
Stanislaus
StB -
Santa Barbara
Su -
Sutter
Te -
Tehama
Tr -
Trinity
Tul -
Tulare
Tuo -
Tuolomne
Ve -
Ventura
Yo -
Yolo
Yu -
Yuba