The Kobuk River (also Kooak, Kowak, Kubuk, Kuvuk, or Putnam) is a river located in the Arctic region of northwestern Alaska in the United States. It is approximately 280 miles (451 km) long. Draining a basin with an area of 12,300 square miles (32,000 km²), the Kobuk River is among the largest rivers in northwest Alaska with widths of up to 1500 feet (460 m) and flow at a speed of 3–5 miles per hour (5–8 km per hour) in its lower and middle reaches. The average elevation for the Kobuk River Basin is 1,300 feet (400 m) above sea level, ranging from near sea level to 11,400 feet (3,475 m). Topography includes low, rolling mountains, plains and lowlands, moderately high rugged mountainous land, and some gently sloped plateaus and highlands. The river contains an exceptional population of sheefish (Stenodus leucicthys), a large predatory whitefish within the salmon family, found throughout the Arctic that spawns in the river's upper reaches during the autumn.