The Chatanika River is a 128-mile (206 km) tributary of the Tolovana River in the U.S. state of Alaska. The Chatanika River is a clear or lightly tannic stained rapid-runoff stream that has its headwaters in the mountains of the northeastern portion of the Alaska Range and flows westward through valleys between summits and uplands for about four-fifths of its length before it enters Minto Flats. Once in the flats—a marshy area in which multiple streams, rivers, and lakes are located— the Chatanika joins the Tolovana, which flows into the Tanana River and on to the Yukon River.