San Nicolas Island


San Nicolas Island at a Glance

County: Ventura County 
Distance to the nearest Island: 21 miles to Santa Catalina Island
Distance to the nearest mainland: 61 miles to Laguna Point near Point Mugu
Height: Jackson Hill at 905 feet is the highest point
Ownership: United States Government
Government Leases:
1902-1907  W. J. McGimpsey
1907-1909  D. R. Weller
1909-1914  J. G. Howland
1914-1919  J. G. Howland
1919-1924  E. N. Vail
1924-1929  E. N. Vail
1929-1934  E. N. Vail
Size: 22 square miles, it is 5th in size of the 8 California Channel Islands
Public access: None
Public transportation: None
Native terrestrial mammals:
Deer Mouse (Peromyscus maniculatus exterus)
Island Fox (Urocyon littoralis dickeyi)
Native amphibians: 
Island Night Lizard (Xantusia riversiana)
Native Reptiles:
Side-blotched Lizard (Uta stansburiana)
Southern Alligator Lizard (Elegaria multicarinatus)
Endemic Plants:
Trask's Locoweed (Astragalus traskiae)
Buckwheat (Eriogonum grande ssp. tamorum)
Lomatium (Lomatium insulare)

San Nicolas Island is 22 square miles and ranks fifth in size of the California Channel Islands, It is roughly oval in shape, with the axis just under ten miles long, and a maximum width of 3.6 miles. Jackson Hill, at an elevation of 905 feet is its highest point.

San Nicolas Island became US government property when California became a state in 1850. Three years later, Juana Maria, the Lone Woman of San Nicolas Island was removed from the island and taken to Santa Barbara. From 1902 to 1934, the government leased San Nicolas Island to private sheep-ranching interests.

Flora and Fauna:

There are over 200 different plant species which grow on San Nicolas Island, four of which are restricted to San Nicolas: an un-described species of Malacothrix, a member of the sunflower family; a phacelia (Phacelia cinerea); a buckwheat (Erigonum grande timorum); and a box thorn (Lycium verrucosum). The phacelia and the box thorn may now be extinct.

There are two native terrestrial mammals found on San Nicolas Island: the endemic subspecies of island fox (Urocyon littoralis dickeyi); and an endemic species of the deer mouse (Peromyscus maniculatus exterus).

Physiography and Geology:

San Nicolas Island is relatively flat-topped with a mesa-like profile. The western end contains large shifting sand dunes, while the eastern end is very precipitous with a large sand spit extending eastward. The southern or leeward side of the island is a giant excarpment which rises from the sea to 700 feet within a mile of shore. The northern side of the island has cliffs which rise as wave-cut terraces to the mesa at 300-400 feet above sea level.

The bedrock of San Nicolas Island is mainly composed of sandstone of Eocene age that has been carved into wave-cut terraces. Sediments of Pleistocene and Holocene age lay on top. The island is gently folded and intensely faulted. The marine sedimentary rocks forming marine terraces are composed of conglomerates, sandstone, siltstone and shale.