paragraph_text: The Rufiji River lies entirely within Tanzania. The river is formed by the confluence of the Kilombero and Luwegu rivers. It is approximately 600 kilometres (370 mi) long, with its source in southwestern Tanzania and its mouth on the Indian Ocean at a point between Mafia Island called Mafia Channel. Its principal tributary is the Great Ruaha River. It is navigable for about 100 kilometres (62 mi).

paragraph_text: The Little River, a watercourse that is part of the Hawkesbury-Nepean catchment, is located in the Southern Highlands region of New South Wales, Australia.

paragraph_text: Cup and Saucer Creek, an urban watercourse of the Cooks River catchment, is located in the Canterbury-Bankstown region of Sydney, in New South Wales, Australia.

paragraph_text: Toongabbie Creek, an urban watercourse that is part of the Parramatta River catchment, is located in Greater Western Sydney, New South Wales, Australia.

paragraph_text: Coxs Creek, a watercourse of the Cooks River catchment, is located in the Inner West of Sydney, in New South Wales, Australia.

paragraph_text: Arado (plow) River in the north of Portugal. The river's source is the Gerês Mountain, and the mouth cascades into the Fafião river, (41°42'10.88"N; 8° 6'33.50"W), Fafião place, Cabril village, Montalegre municipality. From Arado cascate (41°43'25.53"N; 8° 7'46.98"W) till the mouth, runs .

paragraph_text: Bardwell Creek, an urban watercourse of the Cooks River catchment, is located in the southern suburbs of Sydney, in New South Wales, Australia.

paragraph_text: Wolli Creek () is an urban watercourse of the Cooks River catchment located in the southern suburbs of Sydney, in New South Wales, Australia.

paragraph_text: The Yukon River is a major watercourse of northwestern North America. The river's source is in British Columbia, Canada, from which it flows through the Canadian Yukon Territory (itself named after the river). The lower half of the river lies in the U.S. state of Alaska. The river is long and empties into the Bering Sea at the Yukon–Kuskokwim Delta. The average flow is 6,430 m/s (227,000 ft/s). The total drainage area is 832,700 km (321,500 mi), of which 323,800 km (126,300 mi) is in Canada. The total area is more than 25% larger than Texas or Alberta.

paragraph_text: Bolshaya Lyampa () is a river in Perm Krai, Russia, a right tributary of Uls River which in turn is a tributary of Vishera River. The river is long. Its source is near the border with Sverdlovsk Oblast. It flows into the Uls River from the larger river's mouth. The Bolshaya Lyampa's main tributary is the Malaya Lyampa River.

paragraph_text: Orange Gariep, Oranje, Senqu River Sunset over the Orange River near Upington in the Northern Cape Countries Lesotho, South Africa, Namibia Tributaries - right Caledon River, Vaal River, Fish River (Namibia) Landmarks Gariep Dam, Augrabies Falls Source Thaba Putsoa - location Maloti Mountains (Drakensberg), Lesotho - elevation 3,350 m (10,991 ft) Mouth Alexander Bay - location Atlantic Ocean Length 2,200 km (1,367 mi) Basin 973,000 km (375,677 sq mi) Discharge - average 365 m / s (12,890 cu ft / s) 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).

paragraph_text: The river Loimijoki is a river in Finland and the longest tributary of the river Kokemäenjoki. The river originates at the lake Pyhäjärvi in Tammela and joins the river Kokemäenjoki in Huittinen. There is a difference in elevation between the source and the mouth of the river, which is long. The river drains a catchment area of . The river has several dams at Forssa, Jokioinen and Loimaa.

paragraph_text: Still Fork is a tributary of the Sandy Creek, long, in eastern Ohio in the United States. Via the Sandy Creek, Tuscarawas, Muskingum and Ohio Rivers, it is part of the watershed of the Mississippi River, draining an area of in Carroll County, Ohio. The source is at and the mouth is at ., with an average gradient of only 0.2%. From its source in eastern Carroll County the creek flows northwest through Fox, Washington, Augusta, and Brown Townships before reaching its mouth in Minerva, Ohio. The Ohi-Rail Corporation (OHIC) and Arbor road are situated in the creeks valley over most of its length.

paragraph_text: Upper Orange WMA, or Upper Orange Water Management Area (coded: 13), Includes the following major rivers: the Modder River, Riet River, Caledon River and Orange River, and covers the following Dams:

paragraph_text: The Darling Mills Creek, an urban watercourse that is part of the Parramatta River catchment, is located in Greater Western Sydney, New South Wales, Australia.

paragraph_text: Cabramatta Creek, an urban watercourse of the Georges River catchment, is located in the south-western region of Sydney, in New South Wales, Australia.

paragraph_text: Lansdowne River, a watercourse of the Manning River catchment, is located in the Mid North Coast district of New South Wales, Australia.

paragraph_text: The Reconquista River (Spanish, Río Reconquista) is a small river in the province of Buenos Aires, Argentina. Together with the Riachuelo, it is one of the most contaminated watercourses in the country.

paragraph_text: The Doghole River is a river in the Unorganized Part of Kenora District in Northwestern Ontario, Canada. The river is part of the James Bay drainage basin. It flows from Doghole Lake, where the outlet is part of the Mishkeegogamang First Nation Osnaburgh Indian Reserve No. 63B, to the northeast shore of Lake St. Joseph; oddly, the mouth is not on Doghole Bay, adjacent to the east. Lake St. Joseph is the source of the Albany River, which flows to James Bay.

paragraph_text: The river rises of the western slopes of the Great Dividing Range approximately west of Cairns. The river flows generally northwest to the Staaten River National Park and then west, joined by eleven minor tributaries before reaching its mouth and emptying into the Gulf of Carpentaria. From source to mouth the river's waters overflow into intertwining lagoons that create an enormous wetland sanctuary for a vast array of unique wildlife and plants. When the rains of the wet season cease, the Staaten River retreats from the floodplains and wetlands and becomes little more than a thread trickling down wide sand banks and a string of important lagoon refuges. The river descends over its course.

Question: What is the source of the river that is the mouth of the Caledon River?
Answer: Thaba Putsoa