Riverine rising

[this database taken from Factmonster. Other lists omit Red Rock from the Mississippi-Missouri, don't list them again individually, and list the Murray-Darling as one super-long river]

River	Source	Outflow	mi.	km
Nile	Tributaries of Lake Victoria, Africa	Mediterranean Sea	4,180	6,690
Amazon	Glacier-fed lakes, Peru	Atlantic Ocean	3,912	6,296
Mississippi-Missouri-  Red Rock	Source of Red Rock, Montana	Gulf of Mexico	3,710	5,970
Chang Jiang (Yangtze)	Tibetan plateau, China	China Sea	3,602	5,797
Ob	Altai Mts., Russia	Gulf of Ob	3,459	5,567
Huang He (Yellow)	Eastern part of Kunlan Mts., West China	Gulf of Chihli	2,900	4,667
Yenisei	Tannu-Ola Mts., western Tuva, Russia	Arctic Ocean	2,800	4,506
Paraná	Confluence of Paranaiba and Grande rivers	Río de la Plata	2,795	4,498
Irtish	Altai Mts., Russia	Ob River	2,758	4,438
Zaire (Congo)	Confluence of Lualab and Luapula rivers, Congo	Atlantic Ocean	2,716	4,371
Heilong (Amur)	Confluence of Shilka (Russia) and Argun (Manchuria) rivers	Tatar Strait	2,704	4,352
Lena	Baikal Mts., Russia	Arctic Ocean	2,652	4,268
Mackenzie	Head of Finlay River, British Columbia, Canada	Beaufort Sea  (Arctic Ocean)	2,635	4,241
Niger	Guinea	Gulf of Guinea	2,600	4,184
Mekong	Tibetan highlands	South China Sea	2,500	4,023
Mississippi	Lake Itasca, Minnesota	Gulf of Mexico	2,348	3,779
Missouri	Confluence of Jefferson, Gallatin, and Madison rivers, Montana	Mississippi River	2,315	3,726
Volga	Valdai plateau, Russia	Caspian Sea	2,291	3,687
Madeira	Confluence of Beni and Maumoré rivers, Bolivia–Brazil boundary	Amazon River	2,012	3,238
Purus	Peruvian Andes	Amazon River	1,993	3,207
São Francisco	Southwest Minas Gerais, Brazil	Atlantic Ocean	1,987	3,198
Yukon	Junction of Lewes and Pelly rivers, Yukon Territory, Canada	Bering Sea	1,979	3,185
St. Lawrence	Lake Ontario	Gulf of St. Lawrence	1,900	3,058
Rio Grande	San Juan Mts., Colorado	Gulf of Mexico	1,885	3,034
Brahmaputra	Himalayas	Ganges River	1,800	2,897
Indus	Himalayas	Arabian Sea	1,800	2,897
Danube	Black Forest, Germany	Black Sea	1,766	2,842
Euphrates	Confluence of Murat Nehri and Kara Su rivers, Turkey	Shatt-al-Arab	1,739	2,799
Darling	Central part of Eastern Highlands, Australia	Murray River	1,702	2,739
Zambezi	11°21'S, 24°22'E, Zambia	Mozambique Channel	1,700	2,736
Tocantins	Goiás, Brazil	Pará River	1,677	2,699
Murray	Australian Alps, New South Wales	Indian Ocean	1,609	2,589
Nelson	Head of Bow River, western Alberta, Canada	Hudson Bay	1,600	2,575
Paraguay	Mato Grosso, Brazil	Paraná River	1,584	2,549
Ural	Southern Ural Mts., Russia	Caspian Sea	1,574	2,533
Ganges	Himalayas	Bay of Bengal	1,557	2,506
Amu Darya (Oxus)	Nicholas Range, Pamir Mts., Turkmenistan	Aral Sea	1,500	2,414
Japurá	Andes, Colombia	Amazon River	1,500	2,414
Salween	Tibet, south of Kunlun Mts.	Gulf of Martaban	1,500	2,414
Arkansas	Central Colorado	Mississippi River	1,459	2,348
Colorado	Grand County, Colorado	Gulf of California	1,450	2,333
Dnieper	Valdai Hills, Russia	Black Sea	1,419	2,284
Ohio-Allegheny	Potter County, Pennsylvania	Mississippi River	1,306	2,102
Irrawaddy	Confluence of Nmai and Mali rivers, northeast Burma	Bay of Bengal	1,300	2,092
Orange	Lesotho	Atlantic Ocean	1,300	2,092
Orinoco	Serra Parima Mts., Venezuela	Atlantic Ocean	1,281	2,062
Pilcomayo	Andes Mts., Bolivia	Paraguay River	1,242	1,999
Xi Jiang (Si Kiang)	Eastern Yunnan Province, China	China Sea	1,236	1,989
Columbia	Columbia Lake, British Columbia, Canada	Pacific Ocean	1,232	1,983
Don	Tula, Russia	Sea of Azov	1,223	1,968
Sungari	China–North Korea boundary	Amur River	1,215	1,955
Saskatchewan	Canadian Rocky Mts.	Lake Winnipeg	1,205	1,939
Peace	Stikine Mts., British Columbia, Canada	Great Slave River	1,195	1,923
Tigris	Taurus Mts., Turkey	Shatt-al-Arab	1,180	1,899