The East Branch rises near the northern boundary of Jackson, New Hampshire, in an area just south of the Wild River, east of Black Mountain Ski Area, and southwest of the Baldface mountains. The river flows south through the White Mountain National Forest in an area that is devoted more to logging than other portions of the forest. Leaving the forest, the river enters the town of Bartlett, reaching the Saco River at Lower Bartlett village, just downstream of the Ellis River confluence with the Saco.