We tried to stay at a few of the other Mojave Preserve sites listed on the Dyrt (17 mile and Kelso dune)  when traveling between Joshua Tree and Death Valley), but a blown tire on our campervan rental meant that we couldn’t reach any of them as they were all down long dirt roads. With the sun setting and a limping van we had to find a new dispersed location.  [Disclaimer: we wouldn't have camped here unless we had other options. Leaving this review in case someone is in a similar situation— I was scouring Dyrt Pro offline for anywhere to go as we were searching that night and everything needed 4WD or a long drive down a dirt road]

The turn off was Aiken Mine Road and we went down it a bit to get off the main road and find a flat wider spot to safely camp.

Along Hwy 127 between I-40 and I-15 there are a number of  pull offs where you can spend the night in a campervan or RV (I wouldn’t recommend a tent unless you can get further off the road). This space we found was very wide and far enough off the road to be quiet, but not too far that we wouldn't be in trouble with the tire. Only one car passed between sunset and sunrise. There aren't a whole lot of options between Death Valley and Joshua Tree if you're traveling in the shorter days of winter and plan to see one of the parks during the day.

I'd only recommend this option if you just need a place to sleep during the dark hours.

There is actually some decent cell service in the Mojave preserve (along Hwy 127) . There are also call boxes about every 2 miles further along the 127.

Cost=$0 also means no amenities. But there were lots of Joshua Trees to be seen and a very, very beautiful night skies because there is NOTHING out here.