River, east-central Alaska, U.S. Rising from two headstreams fed by glaciers high in the Wrangell Mountains , the Tanana flows northwest 550 mi (885 km) to join the Yukon River ; it is the Yukon's chief southern tributary.
The Tanana was first explored by Russian traders in the mid-19th century. Its valley was an important gold-producing area in the 1904 gold rush ; it is also a lumbering district and one of Alaska's major farming regions. The Alaska Highway follows it for nearly its entire course.