The Mill River Division is located in Northampton and is 249 acres in size. This floodplain forest is a key stopover habitat for migratory land birds and waterfowl during the spring and fall. There are two ponds on the division, Magnolia and Triangle, created during the construction of I-91 that afford resting and feeding habitats for waterfowl. There are no developed trails, but several native surface two-track roads no longer open to vehicles are open to hikers. This division is open to the public for hunting, fishing, wildlife observation and photography, environmental education, and interpretation.

The Silvio O. Conte National Fish and Wildlife Refuge was established in 1997 to conserve, protect, and enhance the abundance and diversity of native plant, fish, and wildlife species and the ecosystems on which they depend throughout the 7.2 million-acre Connecticut River watershed.