It is 5.06 miles (8.14 km) long and runs north–south within the town of Cornwall.

It runs north for 1.7 miles (2.7 km), crosses the Hollenbeck River, continues for another 2.2 miles (3.5 km), then crosses the Hollenbeck River a second time as it enters the village of Cornwall Hollow.

It continues north another 1.2 miles (1.9 km) to an intersection with Route 63 in northern Cornwall just south of the Canaan town line.

Route 43 is known as Cornwall Hollow Road for its entire length.

[2] This resulted in Route 43 being cut back to its current northern terminus.