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River otter in John's River, Washington © Bruce Sanford

River otter populations are now thriving in areas from which they were once locally extinct.

Playful River Otters Found Throughout North America

Found in Alaska, Canada, and much of the United States, the river otter lives, predictably enough, in rivers. It also inhabits lakes, bayous, and marshes, where it usually lives alone, defending its territory from otters of the same sex. Its pelt varies from rich brown to almost black with pale brown on the throat, chin, cheeks, and chin. They grow about 3-4 feet long and may weigh more than 20 pounds, though most are somewhat less rotund. Aided by its webbed toes, a river otter can dive up to 60 feet deep and swim as fast as 7 miles per hour, for a quarter of a mile before coming up to breathe. 

River otters move across land as well, sometimes traveling to pools with better food supplies in the winter. When crossing ice, they bound a few leaps, then slide up to 22 feet before beginning the process anew. Sliding appears to be one of the otter’s principal activities. They are well known for their “otter slides” on riverbanks, down which they slide into the water, apparently for recreation. River otters also den on the bank, using natural openings, animal burrows, hollow stumps, tree roots, or brush piles, bearing 2-4 young in March or April. Though they don’t reach sexual maturity until 2 years, they disperse in their first fall or winter to their own territories. 

Though the river otter was once extirpated in much of its range, it has been reintroduced to areas and seems to be thriving.  The IUCN lists the species as one of Least Concern, and 29 American states and most Canadian provinces have populations large enough to sustain harvests.