When it rains, it pours. I was walking this morning, only just having seen the muskrat yesterday when I saw the handiwork in this photo. On the other side of the path was a sapling that had been dragged halfway down to the river but had been left behind.

American Mink
As I continued along, I heard a crying, squeaking sound coming from a runoff drain below a walking bridge. I stopped to see if I could find out what was making it. In a minute, the sounds stopped and two animals emerged and swam upstream, towards Fairy Lake. They looked exactly like small otters, about 2 feet long, about 1/3 to 1/2 of which was tail, which makes me think they are American mink (Neovison vison). Since they are predatory carnivores, I have the nasty feeling they surprised something in that hole and killed it.
Beaver Sighting
Further along the path, I saw some ripples emanating from the bank so I stopped and looked around. I saw what must have been a North American beaver ( Castor canadensis ) swimming along with some greenery in its mouth. I wasn’t completely certain until I ran ahead along the path to see it better, and saw a muskrat swimming along on the far side. The beaver came into view and was about 4x as large as the muskrat.
I’m still not 100% sure – I only had my phone and the photos I took are not clear – but the size difference was so significant. It will probably take sitting down on the riverbank early one morning to see if I can capture it with a proper camera.