At 310 acres (1.3 km2), Lake Sebago is the largest lake in Harriman State Park in the U.S. state of New York. The name is Algonquian for "big water". Operated by the Palisades Interstate Park Commission, Lake Sebago is surrounded by picnic lawns and play fields, and is popular with anglers fishing for landlocked salmon, lake trout, bass, perch and sunfish. The lake has a swimming beach, hand boat launch (electric motors only) and cabin camping. Lake Sebago lies near Sloatsburg. It is located just south of Lake Kanawauke and is accessible by auto from Seven Lakes Drive.
The lake was created in 1925 by the Palisades Interstate Park Commission under William A. Welch by building a dam across Stony Brook. The lake filled the former site of the great Emmetfield Swamp as well as a sawmill that is still visible to scuba divers.
The American Canoe Association and the New York chapter of the Adirondack Mountain Club have camps on the lake. The latter is named "Nawakwa", and dates to 1926, while the former, originally built for the Rogers Peet Company, was built in 1928 and was taken over by the ACA in 1933.
In 1927, a camp was built for the employees of four New York City banks. In 1986, the camp was turned over to a concessionaire to offer cabin camping to the public. Also in 1927, New York University opened a camp which they used until 1961; its facilities, too, are presently available to the public.
 Photographs from Lake Sebago
Canada Goose with Goslings
- Myles, William J., Harriman Trails, A Guide and History, The New York-New Jersey Trail Conference, New York, N.Y., 1999.
- Lake Sebago Beach - New York State Office of Parks, Recreation & Historic Preservation
- ADK Camp Nawakwa
- ACA Sebago Canoe Camp
- Baker Cabin Camp
- Sebago Cabin Camp