The Rattle River is a 4.1 mi river in the White Mountains of New Hampshire in the United States. It is a tributary of the Androscoggin River, which flows east into Maine, joining the Kennebec River close to the Atlantic Ocean. The Rattle River rises in the saddle between Middle Moriah and Shelburne Moriah Mountain in the town of Shelburne, within the White Mountain National Forest. The river (better described as a large brook) flows north to the Androscoggin, dropping from 2800 ft to 700 ft above sea level over its length. The Appalachian Trail follows the river from its source to the Androscoggin River valley.