river in eastern Queensland, Australia. It rises in the Carnarvon Range and flows southeast, northeast, and north for about 400 miles (640 km) through a 50-mile-wide valley to join the Fitzroy River near Duaringa. The Dawson Valley Irrigation Project (inaugurated 1923) comprises several weirs and mainly serves cotton and dairy farms. Explored in 1844 by Friedrich Ludwig Leichhardt, the river was named for Robert Dawson, one of the expedition's backers.