Don River

Don River, river in the Soviet Union, about 1,220 mi (1,930 km) long. Rising in the central Russian upland, about 100 mi (160 km) south of Moscow, it flows generally southward, passes through the 100-mi-(160-km-)long Tsimlyansk Reservoir and empties into the Sea of Azov. A canal, built in 1952, connects the Don with the Volga River. Most of the Don is navigable by barges, except in winter, and it can accommodate oceangoing vessels as far upstream as Rostov, at the head of the river's delta outlet. Leading tributaries are the Donets, Khoper, and Voronezh rivers.