Black Rock Canyon campground is located just south of the town of Yucca Valley, off of Highway 62, in the northwest corner of Joshua Tree National Park. This campground isn’t connected to the main park access roads, which means it offers more privacy than most other spots. You can reserve a campsite 6 months ahead of time (or 12 months for group campsite) on recreation.gov.
Joshua Tree’s most extensive trail network is accessible just south of the campground, making this a good choice for those who want to get a few miles of hiking in, but mostly hang around camp.
The road into Black Rock is a mess, so get ready to dodge some HUGE potholes on the drive in. Numerous roads crisscross the campground in a fairly random order, which makes finding your campsite a bit of an adventure. If you can, try to arrive with some daylight left, which helps immensely in finding your campsite.
A dedicated horse campsite is available by reservation only for $20 per night
All that aside, this campground has flush toilets, fire pits, picnic tables, is dog friendly (within the campground), and has a small visitors center in the middle of camp. Stay here if you want a quieter campground with hiking and nearby town amenities. I recommend sites 78-83 and 97 - 99, which are located in the far corner of the campground.
Individual campsites cost $20 per night, and can be reserved up to 6 months in advance.