Rapid City, South Dakota (population ~75,000) serves as the primary urban base for Mount Rushmore visitors. Located 35 km (22 miles) southwest of the memorial via US-16A, it's a 30-40 minute drive through scenic Black Hills terrain.
Keystone (3 miles from Rushmore): Tourist-focused, limited lodging
Hill City (12 miles): Quaint, 1880 Train, wineries
Custer (17 miles): State park access, more lodging
Stay in Rapid City for amenities and flexibility; drive to Rushmore for sunrise (best light, fewest crowds). The memorial is open year-round; the visitor center and trails have seasonal hours.
Rapid City's combination of infrastructure, location, and regional access makes it the logical hub for Black Hills exploration.