Rapid City, "the Summer Playground of America," was founded in 1876 by gold seekers, fueled by a rush to the Black Hills following Gen. George Custer's 1874 expedition. When the railroad arrived a decade later, cattlemen replaced prospectors, and Rapid City remained a hub of activity. By the end of World War I, the popularity of the automobile and newly constructed roads helped to shape area tourism. Mount Rushmore, 23 miles distant, was under construction...