Special Sub-Topic: Tributaries Click Here To Play: Tributaries

The Missouri River, itself a tributary of the Mississippi, forms part of the fourth largest river system in the world. Which of these rivers is, in turn, a tributary of the Missouri?

Platte. The Platte flows through Nebraska and joins the Missouri not far from Omaha. The Cimarron, in Oklahoma, is a tributary of the Arkansas. The Red River of the North flows into the Hudson Bay watershed, while the Salmon, in Idaho, is on the other side of the Continental Divide from the Missouri.

The Ohio River is one of many American rivers that share the name of a state. Which of these rivers, also sharing a state name, is a tributary of the Ohio?

Tennessee. The Tennessee flows into the Ohio at Paducah, Kentucky. The Illinois and Arkansas are both tributaries of the Mississippi. The Alabama joins the Tombigbee to form the Mobile and Tensaw Rivers, which empty into Mobile Bay on the Gulf of Mexico.

Three of these rivers run directly to the sea; the fourth is a tributary of the mighty Amazon. Which river is the tributary?

Xingu. The Xingu flows northward 1300 mi.(2100 km.) and empties into the Amazon about 200 miles upstream from the Amazon's mouth. The Magdalena and Orinoco, principal rivers of Colombia and Venezuela respectively, flow into the Caribbean Sea. The São Francisco, most important river in northeastern Brazil, flows into the Atlantic.

The Paraná is the largest river of Argentina, flowing into the Rio de la Plata estuary. Which of these rivers is a tributary of the Paraná?

Paraguay. The Paraguay runs south through the country of that name, flowing past the capital of Asunción before joining the Paraná. The Madeira and Negro are tributaries of the Amazon, while the Tocantins flows into the Para Estuary adjacent to the Amazon delta.

Each of these rivers in France flowed past scenes of bloody fighting during World War I. Which of these is a tributary of the Seine?

Marne. The Marne joins the Seine at Paris. The Somme flows into the English Channel, while the Meuse flows north through France, Belgium, and the Netherlands (where it is known as the Maas) before emptying into the North Sea. The Moselle (Mosel in Germany) is a tributary of the Rhine.

The Danube flows through many lands representing different languages and ethnicities of eastern Europe. Which of these rivers is a tributary of the Danube?

Sava. The Sava was the major river of the former Yugoslavia, flowing through Slovenia, Croatia, and Serbia before joining the Danube at Belgrade. The Vltava (Moldau in German) is the main river of Bohemia in the Czech Republic; it is a tributary of the Elbe. The Vistula flows through Poland into the Baltic Sea. The Dniester flows through Ukraine and Moldova into the Black Sea.

The Congo is the second-longest river in Africa. Which of these rivers flows into it?

Ubangi. The Ubangi forms part of the border between the Democratic Republic of the Congo (former Zaire) and the Republic of Congo, as well as the Central African Republic. The other rivers are in southern Africa.

Three of these rivers flow directly to the sea; the fourth is a tributary of the Ganges, holy river of India. Which river is the tributary?

Yamuna. The Yamuna flows past Delhi and Agra before joining the Ganges at Allahabad. The Indus flows through Pakistan into the Arabian Sea. The Irrawaddy (now officially the Ayeyarwady) and the Salween flow through Myanmar (formerly Burma) into the Andaman Sea.

The Murray River forms the border between the Australian states of New South Wales and Victoria before flowing into South Australia on its way to the sea. Which of these rivers is a tributary of the Murray?

Darling. The Darling, named after an early governor of New South Wales, is the longest river in Australia, flowing southwest through New South Wales to join the Murray. The Diamantina is a river in Queensland that drains toward the Lake Eyre basin. The Parramatta is the main river that empties into Sydney Harbour. The Swan flows through Perth, in Western Australia.