A GPS device is strongly recommended. Navigation via maps only will be difficult and will greatly increase the time to complete each day's ride. There is no single map that can show the entire route. The maps listed below will help greatly if you plan to travel with or without a GPS.
Free GPS map -Black Hills National Forest Trail GPS Map-
Recommended that GPS users download the free Black Hills National Forest Trail GPS Map at:
Maps for purchase:
Black Hills National Forest- waterproof map (2014) - $13 http://www.blackhillsparks.org/black-hills-national-forest-recreation-map-2001/
Delorme Atlas & Gazetteer- South Dakota ($19.95) https://shop.delorme.com/OA_HTML/DELibeCCtpSctDspRte.jsp?section=10096
All of these suggested maps are free in printed form and are highly recommended:
Motor Vehicle Use Maps (MVUM)
Both of the Black Hills National Forest maps- Bearlodge/Northern Hills & Mystic/Hell Canyon
Custer National Forest (Sioux Ranger District – South Dakota) (MVUM)
Nebraska National Forest (Fall River District)
South Dakota highway map.