The largest animal found at Fort St. Joseph National Historic Site, the moose (Alces alces) is the world's largest living deer - standing almost two metres at the shoulder. It is characterized by its large size, long face with overhanging muzzle, dewlap or 'bell' under the throat, long legs and short tail. The moose is usually dark brown to black, with beige or gray lower legs.

The moose is most active at night but can be seen any time of day. It eats non-grass herbaceous plants in the summer and the bark, twigs and buds of woody plants in the winter.

The male moose, or bull, has large, palmate antlers. It drops its antlers in the fall after the mating season, and re-grows them over three to five months in the spring and summer.

The female, or cow, moose gives birth to one or two calves in May to June. A moose can live up to 20 years in the wild.