Rio Negro
Tributary in South America
The Rio Negro, or Guainía as it is known in its upper part, is the largest left tributary of the Amazon River, the largest blackwater river in the world, and one of the world's ten largest rivers by average discharge. Wikipedia
Mouth: Amazon River
Length: 1,398 mi
Source: Vaupés River
Cities: Manaus, Barcelos, and San Carlos de Río Negro
Discharge: 988,800 ft³/s
Basin area: 266,797 mi²