The Keystone Boardwalk Inn Suites welcomes you to the heart of Keystone the Black Hills Being located on the boardwalk gives you flexibility places you right next to local shops- the 1880 Train- Borglum Museum and fabulous dining. Mount Rushmore is located 2 miles away and Keystone is the closest town to the national monument. In addition we are just minutes away from Custer State Park- Mount Rushmore Cave- and Wind Cave. While in Keystone be sure to visit all the quaint shops and many restaurants all wi.