The Caledon River is a major river located in central South Africa. Its total length is 642 km, rising in the Drakensberg Mountains on the Lesotho border, flowing southwestward and then westward before joining the Orange River near Bethulie in the southern Free State. The river was originally named Prinses Wilhelminas Rivier in 1777, by Colonel R J …The Caledon River is a major river located in central South Africa. Its total length is 642 km, rising in the Drakensberg Mountains on the Lesotho border, flowing southwestward and then westward before joining the Orange River near Bethulie in the southern Free State. The river was originally named Prinses Wilhelminas Rivier in 1777, by Colonel R J Gordon.