At the north end of the lake, Route 8 crosses over the river and very briefly runs atop the county line.

Route 8 crosses the West Branch of the Farmington River a few times as it enters the town of Becket.

In the hamlet of West Becket, which lies just south of the river's source, the highway meets US 20 (Jacobs Ladder Road).

There, US 20 continues east along Chester Road and Route 8 turns north onto Main Street.

Route 8 continues northwest along the river and railroad to the town of Dalton, within which the highway follows Main Street.

Routes 8 and 9 head west and enter the city of Pittsfield along Dalton Avenue.