Assabet River National Wildlife Refuge is one of the more than 550 forests and wetlands protected by the National Wildlife Refuge System and the United States Fish & Wildlife Service in the country. The refuge boasts 20 nature trails ranging in distance from 0.3 to 2.3 miles. All trails meander through the park's wetlands, bogs and forested area, where hikers and spectators may encounter a variety of migratory birds and various species of indigenous mammals, replites and fish. Permit holders may hunt and fish on the refuge and will be subject to regulations.