US 7 enters Massachusetts in the town of Sheffield and remains a two-lane road until Lenox. There, a four-lane bypass of Lenox was built in two pieces, and the old US 7 is now Route 7A. US 7 continues on as a four-lane road to Pittsfield, where it is then a three-lane road, narrowing to two lanes for a short time, then widening to four lanes in downtown Pittsfield. US 7 leaves downtown Pittsfield as a two-lane surface arterial, and continues as a rural highway with occasional three-lane stretches for climbing the grades along the Berkshires. It passes west of Mount Greylock before passing through Williamstown, connecting the Taconic Trail with the Mohawk Trail. The road passes Williams College before entering Vermont.'