At one time there was an estimated 60-million beavers in North America -- 50 per square mile in favorable habitat. By 1900, all but a few beavers had been exterminated in the south and east. Since then they have come back, and reached nuisance status in some areas.

The beaver is the largest rodent in North America, weighing from 26 to 90 pounds. Its stout, dark brown body is short-necked with a large rounded head and small eyes. The beaver is perfectly equipped for its life in and around the water. Its webbed hind feet and large horizontally-flattened tail aid it swimming in its watery habitat in and along streams, rivers, lakes, swamps and marshes. Its tail is used as a rudder and, when threatened, it signals danger by slapping it on the water when diving. The beaver's ears and nose have valves that close when it submerges.

The beaver can use its front feet for digging, combing and spreading oil on its fur and handling food and construction materials for its lodge. It constructs its den as a dam on a creek to form its own pond, or it builds along a river or lake bank. The lodge may measure seven feet high and 40-feet in diameter with about a 3 X 5 foot living space inside.

The beaver's large incisor teeth are capable of cutting a five inch diameter willow with ease. One beaver in British Columbia felled a 110 ft high cottonwood which was 5' 7" in diameter. Cottonwood, willow, aspen and yellow pond lily are among its favored foods.

A beaver colony is made up of a male, female, yearlings and kits. The female has a single litter of three to four kits in April to June after which the male leaves for the season. As the males grow they have to spread out to find their own territory. This leads to the establishment of new colonies.