A Back Country Road in JT
Pinkham Canyon Road in Joshua Tree national Park, is an excellent way of seeing the park's southern landscape without the crowds. The NPS lists this trail as challenging and 4wd required. However, I think the majority of the trail could be done in 2wd as long as you have enough clearance. The first section of the road is double track then once you make it into Pinkham Canyon you will be in a sandy wash with some rocky areas. At places the sand can be somewhat deep.
The road begins directly across from the Cottonwood visitors center near the south entrance of the park off I-10. Its a dirt road marked by a "4wd required" yellow sign. There is also an information sign explaining the history and sites along with a map. The first section is 7 miles until you enter Pinkham Canyon, its 20 miles total from the start to I-10, you can also choose to take the BLM road that parallels I-10 back to the park entrance. I chose this route as it keeps you on all dirt for a nice 30 mile loop. If you bring the BLM road back you can also scope out some of the campsites available outside the park. While in Pinkham canyon you have the option to include Thermal canyon as well, this would add extra miles and could also be a way to do a lollipop loop and come back the way you came. Lots of options.
We saw two other vehicles while out there, and while not a hard trail, you should always go prepared. It may be a while before someone else comes along. This could also be used as an alternative entrance or exit to the park. Also since biking is only allowed on designated roads inside the park, this could also be explored on a Mountain Bike.
Check out the Triplogs.