Jumbo Rocks Campground lies amid the huge, steep rock formations for which Joshua Tree National Park is known. Close proximity to many boulders and rock formations, it is a popular camping location for families with kids. Jumbo Rocks is one of four campgrounds in the park that can be reserved during the busy winter season; it is open on a first-come, first-served basis from June 1 through September 29. Travelers who enjoy warm, dry winters flock to Joshua Tree from October through May, when temperatures hover between 70-90 degrees during the day and drop to a 40-60 degree range at night. Summer is the park's off-season due to the uncomfortably-high desert heat. Jumbo Rocks is at an elevation of 4,380 feet. There are no electric, water or sewer hook-ups available at individual campsites; nor is there a dump station located nearby. Potable water is available at the Oasis Visitor Center. If arriving one or more days late, call (760) 367-5554; your reservation will be forfeited if you do not call or visibly occupy your campsite within 24 hours of your arrival date. Fall and spring are the busiest times of year and reservations often book up early; if the reservable campgrounds are full, call the campground ranger station directly at (760) 362-4367 to check availability at other campgrounds within the park or nearby local community areas. All organized events require a special use permit and must be held in designated areas; call (760) 367-5518 for more information. Resale or auction of advance reservations is prohibited. Gathering firewood is not allowed in the park. Pets are not allowed on trails but are welcome in the campground, on any dirt road or within 100 feet of any road. For additional park information, call (760) 367-5522 or visit www.nps.gov/jotr .