North American beaver (Castor canadensis) 2015-5-8 Patuxent Research Refuge, Anne Arundel County, Laurel, MD

The lodge and chewed tree were found at separate locations on the driving loop.
Beavers make their entrance under water.
Now all I need is a picture of the actual Beaver!
This is the first Beaver lodge I've seen, so I don't have any experience knowing if it's active or old.