In Snohomish county there's a small lake called Lake Cassidy. I live on that lake. Down the road from my place theres the only stream that drains the lake, it's call Catherine Creek. In the 1st mile of that stream there's around 40 beaver dams that are a constant PITA, causing water over the roadway and floods all the time
I have no idea of the legality of trapping the furry *censored*s, but they are sure in residence, in good numbers.