Dunbar Cave was a popular resort for many years before becoming a state park. Beginning in 1875, investors created opportunities to stay at Dunbar Cave and the nearby Idaho Springs. Over the following 60 years, cabins were built, a wooden dance floor was constructed at the mouth of the cave, and an artificial lake was created.
In 1931, the Dunbar Cave and the Idaho Springs Corporation bought the cave and surrounding land. They added electric lights in the cave, a swimming pool and bathhouse, and a concrete dance floor and bandstand at the cave mouth. They also enlarged the artificial lake. Big bands played there, including Benny Goodman, Glenn Miller, Lena Horne, and Tommy Dorsey. Country musician Roy Acuff purchased the site in 1948. Over the July Fourth weekend in 1948, Acuff publicized his new ownership by booking Owen Bradley and his orchestra on July 3. Acuff himself headlined a show on the Fourth, followed by fireworks.
Acuff made Dunbar his home base when he wasn’t touring and made several additions to the resort, such as a 1,300-seat amphitheater on the east side of the lake to accommodate the attendance to the new country shows and a golf course. Grand Ole Opry stars performed at Dunbar Cave on Sunday afternoons. Square dances were held in front of the cave on Tuesday and Friday nights with popular music dances on Saturdays. Acuff sold the resort in 1966 and the state bought the property in 1973. Today, it operates through the Department of Environment and Conservation as a state park to preserve and protect the cultural, natural, and historical resources of Dunbar Cave.