St. Mary's River State Park is separated into two areas, Sites 1 and 2. The Site 1 area holds the 250 acre St. Mary's Lake. Located along Maryland Route 5, between Leonardtown and Great Mills, at the end of Camp Cosoma Road, the area has become a popular freshwater fishing spot. Several species of fish are common to the lake including largemouth bass, chain pickerel, crappie, bluegill and sunfish. The lake has been designated a trophy bass lake and as such, special fishing regulations may be in effect.
Fishermen should check bulletin boards or contact park personnel for details. An 11.5 mile trail circles the lake, allowing the area to be fished from shore or by boat. The trail is regularly used for hiking, biking and horseback riding. The Site 1 area has been improved by a modern comfort station, picnic tables, playground, boat launch ramps and a large, gravel parking lot. Picnicking is permitted but tables are limited.
Site 2 covers approximately 2,200 acres and is primarily undeveloped. It is a wildlands area and a managed hunting area. Small game such as rabbit and squirrel, as well as white-tailed deer are found here. Hunting with a firearm is permitted. You may hunt with bow and arrow during the regular archery season for deer. Parking is permitted in designated areas only.