Greenwell State Park is located on the Patuxent River in St. Mary’s County and is named for the Greenwell family who donated their farm to the state for use as a public park. The property includes the historic Rosedale Manor House and use used for a variety of outdoor recreational activities. This beautiful hike travels through fields, meadows and woods, and offers dramatic views of the river, with visits to two historic barns. Swimming on the Patuxent River is very popular.