Arches has one 50-site campground, Devils Garden, 18 miles from the park entrance. This is a year-round, limited-facility campground for RV and tent camping. RVs are limited to 30 feet. No dump stations are on site. The busy season for the park is between March and October, and reservations are recommended during this time because the campground is usually full during these months. During the off-season, a limited number of campsites are available on a first-come, first-served basis. Reservations must be made through Recreation.gov or by calling 877-444-6777.
Arches is smaller than Utah's other four national parks, so backcountry camping options are limited. Backpackers aren't out of luck, though, if they follow the rules for primitive camping in the park. First, you must get a backcountry permit at the visitor center. It doesn't cost anything. Your campsite should be established by sundown a half-mile away from trails, a mile away from roads and out of sight of the arches. Keep in mind, this is a desert with little tree cover and extreme temperature fluctuations between day and night. Sudden storms and flash flooding are common. Backcountry camping in this type of environment should only be attempted by experienced backpackers.
Staying in Moab might be more convenient than staying inside the park for many campers. For RVers, the privately run Moab campgrounds have more facilities that big rigs need, including full-hookup sites. Canyonlands Campground (canyonlandsrv.com) is notable because it's in the heart of town within easy walking distance to shops and restaurants. North of town, two miles from the entrance to Arches, Riverside Oasis (riversideoasis.com) has RV and tent sites available near the banks of the Colorado River.
The Bureau of Land Management maintains many campgrounds and camping areas near Arches, including along the Colorado River, which marks the southern boundary of the park. State Highway 128 meanders alongside the river off U.S. 191 north of Moab. Along this section of 128 you'll find five campgrounds and two camping areas within the first 8 miles -- the first is called Goose Island, the last Upper Big Bend. RVs are allowed in the campgrounds, but no hookups are available. You can't make reservations for these first-come, first-served sites, but you will have to pay a fee.