Pen Mar Park is a scenic area in Pen Mar, Washington County, Maryland. It is located on High Rock Road adjacent to the Mason–Dixon line. In 1877, the site was opened as an amusement park and resort area by the Western Maryland Railway (WM). During the summer months the railroad offered frequent train service on its "Blue Mountain Express" from Baltimore to Pen Mar. The WM also ran trains from Hagerstown, Maryland to Pen Mar.
By the turn of the century, the Pen Mar area had become one of the most popular resort destinations in the eastern United States. Weekday crowds in the summer were often 4,000 to 5,000. The single day park attendance reached close to 20,000 visitors. Many hotels and over 100 boarding houses were built to accommodate the visitors to Pen Mar. Prominent among these lodgings was the Blue Mountain House, built by the WM in 1883, which accommodated 400 guests.
The WM sold the park in 1930, and the park closed entirely in 1943. By that time the park had contained a roller coaster, carousel, miniature train and railroad station, a dining hall seating 450 people, and a dance pavilion.
The park was reopened as a county park in 1977. In 1980 a group of citizens from both Pennsylvania and Maryland raised funds to build a multipurpose, public pavilion at the site of the original dance pavilion. The county currently sponsors dance concerts with live music in the pavilion during the spring, summer and fall seasons. Other attractions include recreation areas in the county park; the Appalachian Trail, which passes through the area; and nearby High Rock Summit in South Mountain State Park. The summit is at an altitude of 1,800 feet (550 m), and provides an outlook from the top of Quirauk Mountain.
Coordinates: 39°43′01″N 77°30′29″W / 39.71694°N 77.50806°W