At 250 acres, this fresh water marsh is one of the largest on the Potomac River. The appearance of the marsh changes dramatically through watch season of the year. In summer, dragonflies streak across a blanket of pond lilies. You can find active beaver lodges with freshly cut sticks and an occasional muskrat roaming about. Fruiting wild rice, an important food source for wintering waterfowl can be seen in tall clusters. Through the fall and spring, migrating ducks, raptors, and songbirds stop at the marsh to rest on their long journey. During the winter, snow white tundra swans are joined by large numbers of ducks and Canada geese.