- a river flowing E from NW Texas along the S boundary of Oklahoma into the Mississippi River in Louisiana. About 1300 miles (2095 km) long.
- Also called Red River of the North. a river flowing N along the boundary between Minnesota and North Dakota to Lake Winnipeg in S Canada. 533 miles (860 km) long.
- Also called: Red River of the South a river in the S central US, flowing east from N Texas through Arkansas into the Mississippi in Louisiana. Length: 1639 km (1018 miles)
- a river in the northern US, flowing north as the border between North Dakota and Minnesota and into Lake Winnipeg, Canada. Length: 515 km (320 miles)
- a river in SE Asia, rising in SW China in Yunnan province and flowing southeast across N Vietnam to the Gulf of Tongkin: the chief river of N Vietnam, with an extensive delta. Length: 500 km (310 miles)Vietnamese name: Song Koi