Jewel Cave National Monument in South Dakota has neither in-park lodging nor camping. However, localities outside the park offer both brick-and-mortar places to overnight as well as campsites for parking your RV or setting up your tent.
For standard hotel/motel lodging, Custer, South Dakota, offers the widest choice of places to stay closest to Jewel Cave. You might also consider lodging 35 miles (56 km) away from Jewel Cave in Keystone, South Dakota, near Mount Rushmore National Memorial. Newcastle, Wyoming does have some lodging, as well.
In addition to The U.S. Forest Service-managed Comanche Park Campground 6.5 miles (10.5 km) west of Custer, there are several campgrounds at Custer State Park, 16 miles (26 km) east of Jewel Cave, and some private campgrounds around Custer, South Dakota, as well as the Custer/Mount Rushmore KOA. You might also consider Wind Cave National Park’s Elk Mountain Campground, approximately 30 miles (48.3 km) from Jewel Cave.