River otters vanished from Ohio’s waterways by the mid-1900s, wiped out by pollution and unregulated trapping. Wildlife managers began reintroducing them along streams and marshes in the 1980s, and the 186 records gathered since 2000, including sightings around Ottawa National Wildlife Refuge and Mentor Marsh, trace that slow recovery rather than an unbroken native population.
Records cluster in the colder months, with January and December standing out alongside a spring bump. Otters stay active under ice through winter, and their tracks, slides, and scat are far easier for people to notice in snow than the animals themselves are to spot swimming. NatureServe currently ranks the species S3, vulnerable, in Ohio, a reminder that the comeback is real but still incomplete.
