Seneca Creek State Park

About this park

Seneca Creek State Park, opened in 1958 as Seneca State Park, spans more than 6,300 acres along 14 miles of Seneca Creek as it winds toward the Potomac River in suburban Montgomery County near Gaithersburg. Its close proximity to the Washington, D.C. suburbs makes it one of the busiest and most convenient nature escapes for a huge population base, particularly in autumn when its wooded shoreline draws steady crowds for fall foliage. The park's centerpiece is 90-acre Clopper Lake, popular for fishing, paddle boating, and shoreline picnicking, with several miles of trails circling the water through mixed hardwood forest. Within the park lies the Seneca Quarry, a 19th-century sandstone quarry whose distinctive reddish "Seneca stone" was used in numerous prominent Washington, D.C.-area buildings; the restored quarry master's house still stands on park grounds as a reminder of that industrial history. Leashed dogs are welcome throughout the park, including limited off-leash swimming areas near the lake, making it a popular spot for local dog owners in addition to hikers, anglers, and picnickers. Given its size and suburban location, Seneca Creek functions as a genuine day-use anchor for Montgomery County residents, offering a scale of green space and trail mileage rare this close to a major metropolitan area.