Biologist Kristin Evered spent much of this summer battling beavers in the Puyallup River watershed. The woman versus rodent scrimmage was over a dam that was drastically changing acres of wetlands.

DALLAS — Felled trees. Gnawed tree stumps. Leftover wood chips. These are all signs that you’ve probably got a colony of busy beavers on your hand, particularly if you live near water. And while these ...