<Tr> <Th> 31 </Th> <Td> Niobrara River </Td> <Td> Missouri River </Td> <Td> 7002568000000000000 ♠ 568 mi 914 km </Td> <Td> 42 ° 49 ′ 15" N 104 ° 38 ′ 50" W ﻿ / ﻿ 42.82083 ° N 104.64722 ° W ﻿ / 42.82083; - 104.64722 ﻿ (Niobrara River (source)) </Td> <Td> 42 ° 45 ′ 58" N 98 ° 02 ′ 50" W ﻿ / ﻿ 42.76611 ° N 98.04722 ° W ﻿ / 42.76611; - 98.04722 ﻿ (Niobrara River (mouth)) </Td> <Td> 7004126000000000000 ♠ 12,600 mi 32,600 km </Td> <Td> 7003170000000000000 ♠ 1,700 ft / s 49 m / s </Td> <Td> Wyoming, Nebraska </Td> </Tr> <Tr> <Th> 32 </Th> <Td> Little Missouri River </Td> <Td> Missouri River </Td> <Td> 7002560000000000000 ♠ 560 mi 900 km </Td> <Td> 44 ° 32 ′ 25" N 104 ° 59 ′ 57" W ﻿ / ﻿ 44.54028 ° N 104.99917 ° W ﻿ / 44.54028; - 104.99917 ﻿ ("Little Missouri River (source)) </Td> <Td> 47 ° 36 ′ 38" N 102 ° 52 ′ 24" W ﻿ / ﻿ 47.61056 ° N 102.87333 ° W ﻿ / 47.61056; - 102.87333 ﻿ (Little Missouri River (mouth)) </Td> <Td> 7003831000000000000 ♠ 8,310 mi 21,500 km </Td> <Td> 7002450000000000000 ♠ 450 ft / s 13 m / s </Td> <Td> Wyoming, Montana, South Dakota, North Dakota </Td> </Tr> <Tr> <Th> 33 </Th> <Td> Sabine River </Td> <Td> Gulf of Mexico </Td> <Td> 7002553000000000000 ♠ 553 mi 890 km </Td> <Td> 32 ° 48 ′ 29" N 95 ° 55 ′ 14" W ﻿ / ﻿ 32.80806 ° N 95.92056 ° W ﻿ / 32.80806; - 95.92056 ﻿ (Sabine River (source)) </Td> <Td> 29 ° 59 ′ 08" N 93 ° 47 ′ 26" W ﻿ / ﻿ 29.98556 ° N 93.79056 ° W ﻿ / 29.98556; - 93.79056 ﻿ (Sabine River (mouth)) </Td> <Td> 7003975600000000000 ♠ 9,756 mi 25,268 km </Td> <Td> 7003840000000000000 ♠ 8,400 ft / s 238 m / s </Td> <Td> Texas, Louisiana </Td> </Tr> <Tr> <Th> 34 </Th> <Td> Red River of the North </Td> <Td> Lake Winnipeg </Td> <Td> 7002550000000000000 ♠ 550 mi 890 km </Td> <Td> 46 ° 15 ′ 52" N 96 ° 35 ′ 55" W ﻿ / ﻿ 46.26444 ° N 96.59861 ° W ﻿ / 46.26444; - 96.59861 ﻿ (Red River of the North (source)) </Td> <Td> 50 ° 23 ′ 47" N 96 ° 48 ′ 39" W ﻿ / ﻿ 50.39639 ° N 96.81083 ° W ﻿ / 50.39639; - 96.81083 ﻿ (Red River (mouth)) </Td> <Td> 7005111000000000000 ♠ 111,000 mi 287,500 km </Td> <Td> 7003830000000000000 ♠ 8,300 ft / s 236 m / s </Td> <Td> North Dakota, Minnesota, Manitoba </Td> </Tr>

Map of the main rivers in the usa