It is a tributary of the Connecticut River, which flows to Long Island Sound.

The river flows west through the town of Newport and the city of Claremont.

Numerous falls and steep drops on the Sugar River have led to hydro-powered industrial development.

The upper Connecticut River valley is the ancestral home of the Abenaki people.

A significant prehistoric native american site, the Hunter Archeological Site, is located at a series of terraces near the mouth of the Sugar River.