Elk Hills Naval Petroleum Reserve #1 and #2

This vast area, which is primarily an Atriplex-desert grassland, is one of the last refuges for several animal species which are dependent upon the native vegetation of the San Joaquin Valley. Two of these species, the rare San Joaquin kit fox, Vulpes macrotis mutica, and the endangered blunt-nosed leopard lizard, Crotaphytus silus, are found in this area in comparative abundance.

Vegetation includes saltbush, Atriplex polycarpa, bladderpod, Isomeris arborea, cheese-bush, Hymenoclea salsola, locoweed, Astragalus lentiginosus, bladder sage, Salazaria mexicana, as well as numerous annuals and grasses including Achnatherum speciosum, Nassella pulchra, hair grass, Deschampsia elongata, and the ubiquitous non-native Avena barbata. The rare Eriogonum gossypinum is known from several localities in the Reserve.

There is an abundant fauna in the area, including the San Joaquin and giant kangaroo rats, Dipodomys nitratoides and Dipodomys ingens, San Joaquin antelope ground squirrel, Ammospermophilus nelsoni, badger, Taxidea taxus, desert horned lizard, Phrynosoma platyrhinos, Western whiptail, Cnemidophorus tigris, and Western rattlesnake, Crotalus viridis, among others. The rare prairie falcon, Falco mexicanus, has been observed here.

The Elk and Buena Vista Hills are anticlines formed of Plio-Pleistocene non-marine sedimentary deposits. The creek beds and washes are of Quaternary alluvium, forming a rather extensive fan in Buena Vista wash.

Integrity: There are roads and other developments in the area, including heavy petroleum drilling in the Buena Vista area and minimal in the Elk Hills area, but much of the area is undisturbed. As it is anticipated that drilling in the Reserve will be increased, it is to be hoped that the operations will be clustered insofar as possible to reduce the impact on the habitat.

Use: Present

Ref: Woodring, W. P., P. V. Roundy and H. R. Farnsworth, 1932. Geology and Oil Resources of the Elk Hills, California, including Naval Petroleum Reserve No. 1. U.S. Geol. Surv. Prof. Paper No. 195, 170 pp

March 1976