Currently there are two different species of beaver , the American beaver ( C. canadensis ) and the European beaver ( C. fiber ) . The North American Beaver ( Castor canadensis ) , also called the Canadian Beaver ( which is also the name of a subspecies ) , American Beaver , or simply Beaver in North America , is native to Canada , much of the United States and parts of northern Mexico . The chief feature distinguishing C. canadensis from C. fiber is the form of the nasal bones of the skull .