L. canadensis currently occurs throughout the United States of America and Canada. Originally this species is thought to have ranged from 250-700 N latitude and from 530 to 1660W longitude. In the USA, this species is present in states bordering the Great Lakes, Atlantic ocean and Gulf of Mexico, and in the forested regions of the Pacific coast in North America (Lariviere and Walton 1998). It is also present throughout Alaska, including the Aleutian Islands and the north slope of the Brooks Range (Magoun and Valkenburg 1977). Urbanization and pollution caused reductions in range area and are now absent or rare in Arizona, Hawaii, Indiana, Iowa, Kansas, Kentucky, Nebraska, New Mexico, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, and West Virginia (Melquist and Dronkert 1987; Park 1971; Polechla 1990). Reintroductions have expanded the distribution of this species in recent years, especially in the Midwestern United States (Melquist and Dronkert 1987). In Canada, North American river otters occupy all provinces and territories, except for Prince Edward Island (Melquist and Dronkert 1987).