He was living in Custer County in the southern Black Hills by 1880, and settled in Pleasant Valley in 1884 where Twelve Mile Ranch is today.
Heumphreus provided sleeping accommodations and meals for freighters and lone horsemen and a stable of fresh horses for stagecoaches before they continued the 300-mile (480 km) journey between Cheyenne, Wyoming, and Deadwood.
Hundreds of travelers sought shelter and rest at Twelve Mile and protection from Native Americans and highwaymen throughout the 1880s until the stagecoach route was disbanded in 1887.
In the 1930s, Twelve Mile expanded into a dude ranch, hosting hundreds of people from all over the country, including Sen. Francis Case, South Dakota Gov.
Dr. Barnett Cohen, a bacteriologist from Johns Hopkins University School of Medicine who performed the first ultra-microscopic surgeries, visited the ranch almost every summer in the 1930s and 1940s.