Mountains to Gorham, where the highway intersected Route 16 and followed the Androscoggin River into Maine. Route 15 joined with Route 26 between Bethel and Newry and left the valley of the Androscoggin River at Dixfield. The highway continued through Farmington and entered the Kennebec River valley at Norridgewock, where the route joined Route 20 to Skowhegan. Route 15 passed through Pittsfield and Newport before reaching Bangor, where the highway connected with Route 1. While Route 1 headed back Down East in both directions, Route 15 headed north through the Penobscot River valley through Milford and Enfield. The highway left the Penobscot valley at Mattawamkeag and curved northeast through Island Falls. Route 15 passed through Houlton, where the highway intersected Route 24, before entering New Brunswick. Route 15 was replaced by Vermont Route 15 and U.S. Route 2. The highway was further superseded by Interstate 95 between Bangor and Houlton. Route 16 Route 16, or the East Side Road, began at Route 1 in Portsmouth, New Hampshire. The highway headed north on the west side of the Piscataqua River and Salmon Falls River and intersected Route 9 in Dover and Route 11 in Rochester. Route 16 passed through the eastern side of the Lakes Region, within which the route received the northern end of Route 28 at Ossipee and joined with Route 25. The highway ran concurrently with Route 18 from Conway to Glen, then crossed the White Mountains at Pinkham Notch on the east side of Mount Washington. Route 16 intersected Route 15 in Gorham and passed through Berlin before reaching its northern terminus at Route 26 at Errol. Route 16 was superseded by New Hampshire Route 16. Route 17 Route 17, or the Westerly Route, began at the New York state line in Egremont, Massachusetts. The highway headed east to Great Barrington, then followed Route 4 south into Connecticut. At North Canaan, Route 17 split from Route 4 and headed southeast through Winsted and Canton into Hartford. The highway joined Route 2 and Route 3 to cross the Connecticut River on the Bulkeley Bridge. In East Hartford, Route 17 split southeast from Route 3 through Marlborough and Colchester. The highway briefly ran concurrently with Route 32 through Norwich, where the highways intersected Route 12. Route 17 continued southeast from Norwich to its eastern terminus at Route 1 in Stonington, Connecticut, just west of Westerly, Rhode Island. Route 17