Joshua Tree National Park- fees:
Entrance Fee: $20 (7-day vehicle permit)
Motorcycle; bicycle, person on foot: $10.
Wikipedia https://en.wikipedia.org/wiki/Skull_Rock
Official Website https://www.nps.gov/jotr/planyourvisit/skullrock.htm
Address Park Blvd, 92239, United States
Coordinates 33°59'51.919" N -116°3'33.883" E