Effectively immediately, campsites at the popular Jumbo Rocks campground in Joshua Tree National Park will be available by reservation only. Visitors will be able to make same-day reservations; however, they must be made prior to entering the park due to lack of cell phone and WI-FI coverage in the park. Park officials say the reservation system will improve campers’ experiences in the park, as a parade of vehicles going through a campground looking for an available campsite is really disruptive to campers. Reservations may be made on recreation.gov.