River Otters are mammals that are relatives of the stoats, weasels, mink, badgers and wolverines. These groups of mammals are known as Mustelids. The Mustelids all have one thing in common, they all have scent glands that they use to mark off their territory. In the wild they live less than 10 years; in captivity they live 10 - 15 years. Range/Habitat: River otters are found along rivers, streams, and lakes and also in estuaries, coastal bogs, and large marine waterways such as Puget Sound and the Strait of Juan de Fuca.