North American Beaver

I saw my first Common Loon and since no one was on the road decided to stop and walk down to the lake to see if I could get better images of it. While standing on the shoreline I started talking to the Loon, telling it how beautiful it was and waiting to see if it would come closer when I heard a noise in the water next to where I was standing. Looking down but otherwise not moving I spied this handsome fellow swimming by and slowly turned my camera on him. It was very large for a Muskrat but seemed too easy-going to be a Beaver. I never saw the tail rise up out of the water so need help identifying whether its was a Muskrat or very friendly Beaver that came to say "Hello".