Rush Lake is a large, wild prairie-pothole lake in Cavalier County, in the far north of North Dakota near Langdon, just south of the Canadian border. At roughly 1,593 acres, it is one of the finest undisturbed prairie wetlands in the state — so important to migrating waterfowl that it was named a National Natural Landmark in 1975. This guide is part of our growing North Dakota Lakes Database.
Rush Lake at a glance
- Location: Cavalier County, near Langdon, far northern North Dakota
- Size: about 1,593 acres — a large, shallow prairie-pothole lake
- Status: National Natural Landmark (designated 1975)
- Value: a major staging area for migrating ducks, geese and other waterfowl
- Access: privately owned — a wildlife and birding landmark, not a developed recreation lake
A National Natural Landmark
Rush Lake is exactly what the prairie-pothole region is famous for: a large, shallow, essentially undisturbed marsh lake filling a glacial depression on the northern plains. The National Park Service designated it a National Natural Landmark in 1975 as “a large shallow, essentially undisturbed prairie pothole lake” and “an important staging area for waterfowl.” Landmarks like this are recognized as some of the best remaining examples of a natural feature — here, the vast wetland complex that makes the Dakotas the continent’s duck factory.
Waterfowl and wildlife
Every spring and fall, prairie-pothole lakes like Rush Lake host huge numbers of migrating ducks and geese that rest and feed on their way along the Central Flyway. The shallow, marshy water and surrounding grassland are prime nesting and staging habitat for waterfowl, shorebirds and marsh birds. For birders and photographers, the sheer abundance of waterfowl is the draw.
Is Rush Lake open to the public?
Rush Lake is in private ownership, so it is not a developed public fishing or boating lake — there is no marina, ramp or day-use area. It is best understood as a natural landmark and waterfowl area rather than a recreation destination. Please respect private property and view the lake and its birds from public roads and rights-of-way.
Good to know
- Not a rec lake: private and undeveloped — a wildlife landmark, best for birding from public roads.
- Best seasons: spring and fall migration, when waterfowl numbers peak.
- Want to fish or boat? See our guides to North Dakota’s public lakes and reservoirs.
Frequently asked questions
Why is Rush Lake a National Natural Landmark?
It was designated in 1975 as a large, shallow, essentially undisturbed prairie-pothole lake and an important staging area for migrating waterfowl — a prime example of the northern prairie wetland ecosystem.
Can you fish or boat on Rush Lake?
No — Rush Lake is privately owned and undeveloped, with no public ramp or facilities. It is valued as a wildlife and birding landmark, best viewed from public roads.
Where is Rush Lake?
In Cavalier County near Langdon, in far northern North Dakota, just south of the Canada–U.S. border.
Related: explore more small lakes of North Dakota, or head back to the North Dakota Lakes Database.
Explore more North Dakota lakes: the largest lakes in North Dakota and the deepest lakes in North Dakota.