The Ammonoosuc rises on the western slope of Mount Washington, in Sargent's Purchase in the White Mountains of southern Coos County. One branch of the river is the outlet of the Lakes of the Clouds in the saddle between Mount Washington and Mount Monroe. Leaving the vicinity of the Presidential Range, the river flows westwardly into Grafton County, where it turns southwestwardly. Along its course the Ammonoosuc passes through Chandler's Purchase, Bean's Grant, and Crawford's Purchase; and the towns of Carroll, Bethlehem, Littleton, Lisbon, Landaff, Bath, and Haverhill to the village of Woodsville, where it flows into the Connecticut River. It collects the Gale River in Lisbon, and the Wild Ammonoosuc River in Bath.