Jumbo Rocks Campground More: Centrally located, Jumbo Rocks Campground offers great opportunities for scrambling around the boulders Joshua Tree National Park is known for. Skull Rock Nature Trail loops near the campground, leading visitors among the rock features and native plants of the area.There are 124 individual/family sites in this campground. All are first come, first served. Site 122 is wheelchair accessible.NPS Photo. Original public domain image from Flickr