St. Mary's River State Park

About this park

St. Mary's River State Park sits at the northern end of the St. Mary's River watershed in St. Mary's County, split into two distinct sites acquired by the state between 1968 and 1983. Site 1 centers on the 250-acre St. Mary's Lake, created in 1975 and located along Route 5 between Leonardtown and Great Mills, while the separate, largely undeveloped Site 2 covers roughly 2,200 acres of forest and wildlands further from the lake. The lake area has become one of southern Maryland's more popular freshwater fishing destinations, supported by a modern comfort station, boat launch ramps, a playground, and picnic tables, and a 7.5-mile trail circles the entire lake for hikers looking for a longer, self-contained loop. The park's undeveloped Site 2 wildlands, by contrast, offer a much quieter, more remote hiking experience with far less infrastructure. Leashed pets are welcome throughout the park, and the automated entrance gate at the lake area accepts only credit, debit, or a park-issued swipe card rather than cash, a detail worth knowing before a visit. Given its position in far southern Maryland near Historic St. Mary's City, the state's first colonial capital, the park makes a natural pairing with the region's deeper colonial-era historic sites for visitors touring St. Mary's County.