North American river otter
River otters were once state-endangered in Virginia (and nearly wiped out in the western part of the state), but reintroduction programs in the 1980’s have been quite successful, and their numbers have recovered significantly (Virginia DWR).
I first observed these graceful semi-aquatic mammals on the North Fork of the Shenandoah in 2010, but it was a number of years until I saw them again. In the last several years, I’ve made a number of observations and have even been able to watch them diving for fish.