Trapping is not allowed in the Mendenhall Glacier Recreation Area. This has allowed a small, but healthy population of both mink and otter. Frequently these two species are mistaken for each other by observers who only rarely see them. Some clues to tell them apart are:
Size - Otters are larger
Nose - Mink have a pointed nose , while otters noses are more rounded
Base of Tail - The base of the otter tail is much thicker than that of a mink
The first two photos below show a mink and the third an otter.