 According to the United States Census Bureau, the town has a total area of 30.8 square miles (79.8 km2), of which 30.6 square miles (79.2 km2) is land and 0.2 square mile (0.6 km2) (0.71%) is water.Dummerston is bounded by the Connecticut River, and the West River flows through the town.The town is crossed by Interstate 91 (Exit 4 serves the town and the exit sits on the border of Dummerston and Putney), U.S. Route 5 and Vermont Route 30.