2,200 km (1,367 mi)
According to the Columbia Encyclopedia, the Orange River is the "chief river of South Africa, c.1,300 mi (2,090 km) long." For more information on this river, see Answers.com via the Related Link.
256 km
the Seine river is 777 km long. The river seine is 776 km long.
The Mississippi River is 5969 km long.
48 Km
The Rhone River is 812 km long
The Orange River is not in miles, but in South Africa.
897 km
2,140 km.
That would be the River Nile, (at the moment) which is 6,650 km long.
The Benue River Is 1400 Km Long