East Mountain is a traprock mountain ridge located in the Connecticut River Valley of Massachusetts. It is part of the narrow, linear Metacomet Ridge that extends from Long Island Sound near New Haven, Connecticut, north through the Connecticut River Valley of Massachusetts to the Vermont border. East Mountain is known for its extensive scenic cliffs, unique microclimate ecosystems, and rare plant communities. It is traversed by the 110mi Metacomet-Monadnock Trail.GeographyEast Mountain rises steeply between 350and above the Connecticut River and Westfield River valleys below; it is roughly long and wide at its widest point, although the steepness of the terrain makes the actual square mileage much larger. The mountain includes many crests and tiered ridges, with a high point of above sea level. Various lakes, ponds and reservoirs are located on it, including Snake Pond, a mountaintop kettle pond.East Mountain extends from the Westfield River on the tri-border of Westfield, West Springfield, and Agawam, Massachusetts to the base of Mount Tom in Holyoke; it lies within the towns of Holyoke, Westfield, West Springfield. The Metacomet Ridge continues north as the Mount Tom Range and south across the Westfield River as Provin Mountain. The west and south sides of the mountain drain into the Westfield River, thence to the Connecticut River and Long Island Sound; the north and east sides of the mountain drain into the Connecticut River.
