In 1922, the road from Woodbridge to Southbury (the old Oxford Turnpike) was designated as State Highway 147 and the road from Southbury to New Milford (via Roxbury and Bridgewater) was designated as State Highway 125. Route 67 was established in the 1932 state highway renumbering from Bridgewater (beginning at modern Route 133, which was then part of an old alignment of Route 25) to New Haven (continuing past Woodbridge along current Route 63). When Route 25 was realigned in April 1943, Route 67 took over the old Route 25 alignment to New Milford.
In 1922, a road from Woodbridge to Southbury (the old Oxford Turnpike) became State Highway 147 and another route from Southbury to New Milford (via Roxbury and Bridgewater) was designated as State Highway 125. Route 67 was established in the 1932 state highway renumbering, starting at modern Route 133 (which was part of an old alignment of Route 25) and continuing to New Haven along current Route 63. When Route 25 was realigned in April 1943, Route 67 took over the old Route 25 route to New Milford.