The main stem continues east into the northern corner of the town of Brunswick, then turns southeast upon entering the town of Bloomfield for its final descent to the Connecticut River at Bloomfield village, across from the village of North Stratford, New Hampshire.

The East Branch of the Nulhegan enters from the north 2 miles (3 km) northwest of Bloomfield village.

The river is part of the Northern Forest Canoe Trail that extends from the Adirondack Mountains to Fort Kent, Maine.

The North Branch of the Nulhegan rises at the mouth of Unknown Pond in the unincorporated area of Averys Gore, Vermont, at an elevation of 2,326 feet (709 m) in a saddle between Middle Mountain to the north and Bluff Mountain to the south.

The East Branch rises in the center of the town of Averill and flows briefly north and west before turning south and southeast for the majority of its course.