In addition to being a public recreation area encompassing more than 6,300 acres along 14 miles of the Seneca Creek in Montgomery County which features trails for hiking, cycling and horseback riding, Seneca Creek State Park is also home to Clopper Lake. More than 90 acres in size, Clopper Lake averages 18-feet in depth with several shallow coves. The Lake has abundant submerged aquatic vegetation, with tree downfalls and beaver lodges providing habitat in some areas of the Lake for bluegill, crappie, redear sunfish, pumpkinseed sunfish, carp, channel catfish and largemouth bass. You can launch your boat via the soft access launch located at the Boat Center or fish from the shoreline. With the surrounding park, this Trail site can keep a family very busy all day long.


There is a fee to enter the state park.

Site Location

Encompassed by Seneca Creek State Park, Clopper Lake is located in northern Montgomery County, just west of Gaithersburg, Maryland.


Seneca Creek State Park 11950 Clopper Road, Gaithersburg, MD 20878

How to Get There

From Interstate 270 just north of Gaithersburg, Maryland, take Exit 12, turning left onto Watkins Mill Road and then take a right onto Clopper Road to the entrance to Seneca Creek State Park in less than a mile.

Parking & Launching

Parking is located adjacent to the lake on a paved lot.  You can launch your boat via the soft access launch located at the Seneca Creek State Park’s Boat Center.

Boat Rentals

Canoes, kayaks, pedal boats and rowboats may be rented at the Seneca Creek State Park’s Boat Center, which is open May through September.

Where to Fish

You can fly fish along Clopper Lake's shoreline, but for the best fly fishing experience, you will need a boat, canoe, kayak or stand-up paddle board. Cast towards the shorelines and on the outer edges of the lily pads, brush, downed trees and other in-water structures.

What to Catch

Bluegill, crappie, channel catfish, largemouth cass, redear sunfish, carp and pumpkinseed sunfish

What to Fish & How

Recommend bringing 5-7 weight fly rods with floating fly lines with 9' leaders with 3x tippets. For largemouth bass and panfish, recommend poppers, wooly buggers, and insect patterns with rubber legs. For catfish and crappie, recommend baitfish patterns including Clouser minnows and Lefty's Deceivers.

Fly Fishing Organizations

Connect with local fly fishing organizations to learn about mentoring opportunities and to connect with others interested in fly fishing.