Moosehorn National Wildlife Refuge is one of the northernmost National Wildlife Refuges in the Atlantic Flyway, a migratory route that follows the eastern coast of North America. The refuge provides important feeding and nesting habitat for many bird species, including waterfowl, wading birds, shorebirds, upland game birds, songbirds, and birds of prey. The East Coast Greenway, connecting Calais, Maine to Key West, Florida, runs through part of the refuge.