Cacapon State Park occupies a long, 6,000-acre strip of land stretching from just south of the Potomac River, which is the border between West Virginia and Maryland, southward to the Virginia state line. The entrance to the park is about 15 miles south of Berkeley Springs, the county seat of Morgan County. The park is bordered on the west by Cacapon Mountain, most of which lies within its borders.

Cacapon State Park came into being in the 1930s when the Civilian Conservation Corps constructed an 11-room log inn in the wide glen at the east side of the mountain. The CCC workers also built a dam and lake, and park facilities soon included a bathhouse, beach, picnic sites, and rental cabins. The park grew in following decades with the construction of new cabins, a maintenance building, and two new residences. A 50-room lodge, complete with a restaurant and banquet hall, was finished in 1956. The lodge was expanded in 1999. The new lodge has eclipsed the original inn, which has nonetheless been carefully maintained and is still rented out for gatherings. In 1973, the park matured into a full-fledged resort with the construction of an 18-hole golf course, designed by Robert Trent Jones Jr.

Today, Cacapon State Park's hiking, family recreation areas, horse trails, and beach draw both vacationers and local people. There are 31 rental cabins. The park's name, taken from the mountain and nearby river, is said to be a derivation of the Shawnee word for "medicine."