The Delamar Valley is a remote, little visited part of eastern Nevada, accessible only by unpaved roads leading off US Route 93, the Great Basin Highway. Turn south onto Powerline Road, just west of Caliente, and you pass through one of the largest concentrations of Joshua Trees in the country. Along the way there are turnoffs to the ghost town of Delamar and its cemetery. If you're heading north, you can travel in the opposite direction by turning west on Alamo Canyon Road, just south of Alamo.
If you go:
You will need a good map "you can pick one up at the BLM office in Caliente" and be sure to carry plenty to drink; this is definitely not a place to get stuck without water.
Links:

Powerline Road
Delamar Valley
Caliente, Nevada 89008 USA
Mailing address:
Bureau of Land Management
Caliente Field Office
U.S. Highway 93, Building #1
Caliente, NV 89008 USA
Phone Numbers:
Bureau of Land Management
+1 (755) 726-8100
+1 (755) 726-8100