Not so. Five minutes (and a quick bit of Googling) later, I discovered that no, beavers weren't only found in NA . . . there is a European species (Castor fiber) which was hunted almost to extinction (and was, in fact, extirpated from many European countries). It's now being reintroduced in some areas.
Cool. You learn something new every day. I hope the reintroductions are successful. ::sending happy thoughts to the newly-discovered (by me!) European beavers:: I've always enjoyed seeing their North American cousins in the wild.