<Table> <Tr> <Td_colspan="2"> Orange </Td> </Tr> <Tr> <Td_colspan="2"> Gariep, Oranje, Senqu </Td> </Tr> <Tr> <Td_colspan="2"> River </Td> </Tr> <Tr> <Td_colspan="2"> Sunset over the Orange River near Upington in the Northern Cape </Td> </Tr> <Tr> <Th> Countries </Th> <Td> Lesotho, South Africa, Namibia </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> Tributaries </Td> </Tr> <Tr> <Td> - right </Td> <Td> Caledon River, Vaal River, Fish River (Namibia) </Td> </Tr> <Tr> <Th> Landmarks </Th> <Td> Gariep Dam, Augrabies Falls </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Source </Th> <Td> Thaba Putsoa </Td> </Tr> <Tr> <Td> - location </Td> <Td> Maloti Mountains (Drakensberg), Lesotho </Td> </Tr> <Tr> <Td> - elevation </Td> <Td> 3,350 m (10,991 ft) </Td> </Tr> <Tr> <Th> Mouth </Th> <Td> Alexander Bay </Td> </Tr> <Tr> <Td> - location </Td> <Td> Atlantic Ocean </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Length </Th> <Td> 2,200 km (1,367 mi) </Td> </Tr> <Tr> <Th> Basin </Th> <Td> 973,000 km (375,677 sq mi) </Td> </Tr> <Tr> <Th> Discharge </Th> <Td> </Td> </Tr> <Tr> <Td> - average </Td> <Td> 365 m / s (12,890 cu ft / s) </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> The course and watershed of the Orange River, Caledon River and Vaal River . This map shows a conservative border for the watershed . Specifically, the Kalahari basin is excluded, as some sources say it is endorheic . Some other sources using computational methods show a basin which includes parts of Botswana (and hence of the Kalahari). </Td> </Tr> </Table> <Tr> <Td_colspan="2"> Orange </Td> </Tr>

What is the source of the orange river