The Taconic Mountains, part of the Appalachian system, run along Massachusetts' western border. These include the state's highest point: Mount Greylock, at 3,491 feet. The Berkshires extend southward from the Green Mountains of Vermont and run down to the border of Connecticut. The Berkshires are separated from the Taconics by the Housatonic-Hoosic valley. The Hoosac Range lies to the east, connecting the Green Mountains to the Berkshires.
At the feet of the Berkshire Mountains lies the Connecticut River Valley, or the Pioneer Valley, as it is known in Massachusetts. This valley formed in the Mesozoic Era. Dinosaur footprints found close to Mount Tom are a testament to this. The Metacomet Ridge extends south through Connecticut to the Long Island Sound estuary. The ridge is home to Mount Tom, Mount Toby and Mount Holyoke. Receding glaciers left moraines that formed a dam in the Connecticut River; this created Lake Hitchcock, which disappeared around 12,000 years ago. Deposits of silt replaced soil lifted away by glaciers, leaving this part of the landscape fertile.
East of the Connecticut River Valley there is an expanse of uplands, lakes and streams that flow into the Connecticut River to the west and the Merrimack, Quinebaug, Blackstone and Charles Rivers to the east. In the east, steep hills rise towards the divide between the basin of the Connecticut River and other eastern river basins. The divide runs through the center of Massachusetts. The highest point east of the Connecticut River is Mount Wachusett, at 2,006 feet.
East of the divide, the height of the land decreases, and the landscape becomes gentler. The landscape near the coast is made up of swamps, marshes, ponds and low hills. The Blue Hills, south of Boston, stand tall above the rest of the landscape; Great Blue Hill, the highest, is 635 feet high. On the coast are many bays, coves and estuaries. Off the coast are a number of small islands, the largest being Plum Island. The Massachusetts coastline is the site of the Cape Cod peninsula; the Cape Cod Chamber of Commerce remarks on its "countless historic sites and landmarks." The coastline was shaped by glacial moraines and the erosion by sand, which also formed its beaches. South of Cape Cod, glacial moraines rise above the sea to shape Martha's Vineyard, Nantucket, the Elizabeth Islands and Monomoy Island.
