In 1877, the site was opened as an amusement park and resort area by the Western Maryland Railway (WM).

[1] During the summer months the railroad offered frequent train service on its "Blue Mountain Express" from Baltimore to Pen Mar.

[3] By the turn of the 20th century, the Pen Mar area had become one of the most popular resort destinations in the eastern United States.

[2]: 246  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 county currently sponsors dance concerts with live music in the pavilion during the spring, summer and fall seasons.