Participants of the Park to Park Ride cycle through Joshua Tree National Park, April 29, 2017. The event, hosted by Natural Resources and Environmental Affairs, Joshua Tree National Park and the city of Twentynine Palms, Calif. took riders from Knott’s Sky Park through Joshua Tree National Park to Keys View and back as the final event of Earth Day celebrations in the month of April. (U.S. Marine Corps photo by Cpl. Dave Flores) - Participants of the Park to Park Ride cycle through Joshua Tree National Park, April 29, 2017. The event, hosted by Natural Resources and Environmental Affairs, Joshua Tree National Park and the city of Twentynine Palms, Calif. took riders from Knott’s Sky Park through Joshua Tree National Park to Keys View and back as the final event of Earth Day celebrations in the month of April. (U.S. Marine Corps photo by Cpl. Dave Flores)