For off-roading in California, here's a great source for that:
http://ohv.parks.ca.gov/
and I have two adventurous routes I drew up in Google Maps at Death Valley
https://maps.google.com/maps?saddr=CA-178+E%2FTrona+Rd&daddr=35.8664114,-117.1780279+to:California+178&hl=en&ll=35.941324,-116.762695&spn=0.887246,2.113495&sll=35.905181,-117.016068&sspn=0.221914,0.528374&geocode=FdBwIAIdULUA-Q%3BFStHIwIdVQEE-SnvKKHqLjPBgDHislmFx1gy7g%3BFbHdJwIdK1IU-Q&mra=dvme&mrsp=1&sz=12&via=1&t=m&z=10
https://maps.google.com/maps?saddr=Co+Route+107&daddr=36.0389158,-118.2594249+to:US-395+N&hl=en&ll=36.095164,-118.143539&spn=0.442759,1.056747&sll=36.039661,-118.208942&sspn=0.110768,0.264187&geocode=FQszJwIdfCjv-A%3BFQPpJQIdIIHz-CkvOjSvKEfAgDFYWGIJSvaSLQ%3BFdSeKQIdyF73-A&mra=dpe&mrsp=1&sz=13&via=1&t=m&z=11
http://ohv.parks.ca.gov/
and I have two adventurous routes I drew up in Google Maps at Death Valley
https://maps.google.com/maps?saddr=CA-178+E%2FTrona+Rd&daddr=35.8664114,-117.1780279+to:California+178&hl=en&ll=35.941324,-116.762695&spn=0.887246,2.113495&sll=35.905181,-117.016068&sspn=0.221914,0.528374&geocode=FdBwIAIdULUA-Q%3BFStHIwIdVQEE-SnvKKHqLjPBgDHislmFx1gy7g%3BFbHdJwIdK1IU-Q&mra=dvme&mrsp=1&sz=12&via=1&t=m&z=10
https://maps.google.com/maps?saddr=Co+Route+107&daddr=36.0389158,-118.2594249+to:US-395+N&hl=en&ll=36.095164,-118.143539&spn=0.442759,1.056747&sll=36.039661,-118.208942&sspn=0.110768,0.264187&geocode=FQszJwIdfCjv-A%3BFQPpJQIdIIHz-CkvOjSvKEfAgDFYWGIJSvaSLQ%3BFdSeKQIdyF73-A&mra=dpe&mrsp=1&sz=13&via=1&t=m&z=11