California Off-Highway Motor Vehicle Recreation division of State Parks
http://ohv.parks.ca.gov/
 
BLM, El Centro Field Office
http://www.blm.gov/ca/st/en/fo/elcentro.html

BLM, Palm Springs - South Coast Field Office
http://www.blm.gov/ca/st/en/fo/palmsprings.html

BLM, Ridgecrest Field Office
http://www.blm.gov/ca/st/en/fo/ridgecrest.html

BLM, Barstow Field Office
http://www.blm.gov/ca/st/en/fo/barstow.html

BLM, Needles Field Office
http://www.blm.gov/ca/st/en/fo/needles.html 

Cleveland National Forest
http://www.fs.fed.us/r5/cleveland/ 

San Bernardino National Forest
http://www.fs.fed.us/r5/sanbernardino/ 

Sequoia National Forest
http://www.fs.fed.us/r5/sequoia/ 

Angeles National Forest
http://www.fs.fed.us/r5/angeles/