The Sibley Lake National Wildlife Refuge is located in the U.S. state of North Dakota and consists of 1,077 acres (4.35 km²). Sibley Lake is a privately owned easement refuge, managed with by the U.S. Fish and Wildlife Service. The refuge was established to protect habitat for migratory bird species, white-tail deer and other mammals. Valley City Wetland Management District oversees the refuge, which in turn is a part of the Arrowwood National Wildlife Refuge Complex. Sibley Lake is a 525 acre (2.12 km²) fresh water marsh.