Seneca Creek State Park in Montgomery County, Maryland, spans more than 6,300 acres and 14 miles of creek corridor, combining protected natural landscapes with extensive recreation. Opened in 1958 and expanded through state-funded land purchases and development in the 1960s, it was transformed in 1975 by the creation of Clopper Lake for recreation and flood control. The park offers boating, fishing, trails, camping, picnicking, horseback riding, and other activities, while also preserving local history through sites such as Seneca Quarry, Black Rock Mill, the Seneca Schoolhouse, and the Woodlands. It remains both a major outdoor destination and a cultural landscape.