In the 1920s, today's Route 183 from Winsted to Colebrook was represented by state highways 174 and 314, funded as a state aid road: improvements were partially funded by the towns. In 1926, a Colebrook lawmaker succeeded in having the road become a trunk line route to the Massachusetts state line; both states proceeded to improve the route as a third road through the Berkshire mountains. The improved access led to a small real estate boom along the road.

Today's Route 183 was commissioned in 1932, from US 44 to the state line. In 1954, it was extended south to Route 4; this might have been done at the same time Route 72 was extended in the area, on May 1, 1954.

The original stone-and-mortar Colebrook Bridge over Center Brook, dating back to 1784, was widened in the late 1980s. Instead of discarding the old stonework, they took it apart and replaced it on the outside of the new structure. This idea earned the state DOT an Award of Merit in Historic Preservation And/Or Cultural Enhancement in 1990.

Extend south along Route 222 and Route 262 to Route 73.

• "Will Build Third Route Through Hills." Hartford Courant, Nov. 1. 1926.

• Route 183 Ends (Photos; Doug Kerr at state-ends.com)