Our property ends about 20 ft shy of a river that rushes and floods halfway up our property and makes it a marshland in spring. In the summer, however, while it still runs fast and is deep in some parts, it's only knee deep where we can cross and explore. It's a good 20+ ft wide, so I've never seen any trace of a beaver dam, but I have seen branches that appeared to have been chewed off by beavers. We have intense winter's with heavy snow and the river does freeze in some parts. Now I'm really curious about these critters. Sounds like a homeschool lesson for the near future!