Forest Road 653.1C is a popular location for dispersed camping close to Custer, SD. Realistically, there is only once place to camp here, which is indicated by the marker on the map below. It's a large enough site suitable for full-sized RVs, and the access road is hard-packed dirt/gravel.
Also known as “Spar Spring – Airport Dispersed Camping” on other campsite maps, this lone site is marked on the Motor Vehicle Use Map for Black Hills National Forest as being open for dispersed camping.
This site lies at the end of Custer Airport, and you will hear prop planes and helicopters taking off and landing throughout the day.
Forest Road 653.1C also gets soggy in wet weather, so be sure to scout this area first if you don’t have 4WD or high clearance.