Its former name Waterford Downs is originated from Al Boyle’s family ancestral home of Waterford, Ireland, which is also the president of the Charles Town Races. Although it was approved to open in 1937, construction only began in 1948 after World War II.

In 1950, its name changed to Waterford Park, and the opening day was finally held on May 19, 1951. Then in the mid-1950s, James F. Edwards purchased the track and was purchased again by Bill Blair and renamed it Mountaineer Park, in 1987. In 1992, the track was sold again to California-based Excalibur Holding Corporation. After two years, the track installed slot machines (making it the first Racino in the US). Excalibur was renamed Winners Entertainment, then renamed MTR Gaming Group. Eldorado Resorts, which merged with MTR Gaming in 2014, sold Mountaineer and two other properties to Century Casinos and Vici Properties in 2019.