The railroad line was originally built by the
Chicago, Burlington and Quincy Railroad (CB&Q) to serve mining and timber interests in the
Black Hills. It reached Keystone on January 20, 1900, and was later used to haul equipment for carving nearby
Mount Rushmore. In 1956, two steam enthusiasts, William Heckman and Robert Freer, promoted to
“have in operation at least one working steam railroad, for boys of all ages who share America’s fondness for the rapidly vanishing steam locomotive.” They soon gathered financial, political and popular support for this venture adjacent to the tourist destination of
Mount Rushmore. The intention was to have summer steam train operations with 1880-period equipment.
Narrow Gauge Heckman and Freer proposed a new three foot gauge
heritage railroad, using the Keystone Branch, by laying a third rail on five miles of the
standard gauge track. CB&Q was supportive, and the dual-gauge line was constructed from Hill City to a new terminus with a
wye, to be named “Oblivion” about midway along the branch. The choice of narrow gauge was influenced by the availability, also from CB&Q, of a complete 1880s styled "
Deadwood Central" trainset which had been assembled for the
Chicago Railroad Fair of 1948–49.
Burlington Northern relocated and rebuilt two miles, to a new Keystone Junction a mile west of the town. During the rebuilding, the BHCR ran its trains out of
Custer, 15 miles south of Hill City on BN's
Deadwood branch. In 1977 the Black Hills Central returned to the Keystone branch, and in 1981 acquired the trackage from BN, which withdrew freight services after its freight traffic had withered away. The last mile was continued into Keystone in 2001. ==Equipment==