Lake Massapoag is actually the middle and largest of three bodies of water, separated at either end by dams.  Flowing north, the upper dam can be opened and the water level dropped by about 6’.  Its residents reside in three towns – Tyngsborough, Dunstable and Groton. 

Massapoag is fed by several Groton lakes - Lost Lake, Knopp's Pond, Whitney (Cow) Pond, Baddacook and Martin's Pond - and empties into Salmon Brook and eventually the Merrimack River.
 
The Club maintains a boat launch located in Tyngsborough at the south end of the lake.  It is open to public boating, with the exception of July and August when the gate is closed and the launch open only to carry-in watercraft.  Please keep the area clean and pack out your trash!

Massachusetts Division of Fisheries and Wildlife stocks the lake with rainbow and other trout at least once yearly.   Go to Mass.gov/trout for regular updates.

The Greater Lowell YMCA operates Camp Massapoag on the Groton/Dunstable side of the lake.  Please check their website for more information:  greaterlowellymca.org
 
In 2018 the lake was treated for the invasive weeds Eurasian milfoil, variable milfoil and fanwort.  Any future treatments affecting recreational use of the lake will be posted around the lake and at the boat launch.  Please make sure your boat is properly cleaned of plants and animals prior to launching.   It’s the law!  (302 CMR 18 MGL)

Please remember to swim safely, keep your boat to the right of the channel (counterclockwise) and watch out for other watercraft.