Taconic Mountains - Geology and Physiography

Geology and Physiography

The Taconic mountain range was formed from the collision of the North American Plate into a volcanic island arc, similar to modern-day Taiwan, during the late Ordovician period, around 440 million years ago.

The western side of the Taconics rise gradually from a series of hills in eastern New York to a sharp mountain crest along the west border of the New England states; the east side of the Taconics falls off abruptly where river valleys divide it from the Berkshires and Green Mountains. The total length of the range is about 200 miles (320 km) with a varying width of 5 to 20 miles (8.0 to 32 km).

The Taconic Mountains are a physiographic section of the larger New England province, which in turn is part of the larger Appalachian physiographic division.