File:Rio Negro basin.jpg|thumb|left|Rio Negro watershed (Interactive map)
Upper course The source of the Rio Negro lies in
Colombia, in the
Department of Guainía where the river is known as the
Guainía River. The young river generally flows in an east-northeasterly direction through the
Puinawai National Reserve, passing several small indigenous settlements on its way, such as Cuarinuma, Brujas, Santa Rosa and Tabaquén. After roughly the river starts forming the border between Colombia's
Department of Guainía and Venezuela's
Amazonas State. After passing the Colombian community of Tonina and Macanal the river turns southwest.
Maroa is the first Venezuelan town the river passes. further downstream the river receives the
Casiquiare canal from the left (north), forming a unique link between the
Orinoco and the Amazon river basin.
Middle course The river now continues in a southeastern direction passing the Venezuelan town of
San Carlos de Río Negro, its largest settlement on the river, and Colombia's
San Felipe. In this stretch the river is constantly fed with tributaries from both sides, and it quickly grows in size creating large river islands, a common feature for all rivers in the Amazon basin. After forming the border between Colombia and Venezuela for the Rio Negro reaches the
Piedra del Cocuy, an igneous rock formation from the Precambrian era, belonging to the
Guyana Shield. Here the
Tripoint of Colombia, Venezuela and Brazil is found in the middle of the river and it now completely enters
Amazonas State, Brazil. After passing
Cucuí, the river continues south, only temporarily turning west for several kilometers. In
Missão Boa Vista the
Içana River joins the Rio Negro and in São Joaquim the
Uaupes River, the largest tributary of the Rio Negro, also enters from the right hand side. The Rio Negro now turns markedly towards the east, forming several rapids and small islets on its way. It then passes
Sao Gabriel da Cachoeira an important commercial city. After several more rapids and imposing views of the Adormecida mountain chain the river leaves the Guyana shield it traversed in its upper and middle course.
Lower course and the Rio Negro at
Manaus,
Brazil.After the
Marié River enters the Rio Negro the river continues its eastward course forming many large islands and becoming very wide at several locations. It passes local communities such as
Santa Isabel do Rio Negro. During the
wet season, the river floods the country far and wide here, sometimes to a width of , for long distances. During this season, from April until October, it is a succession of lagoons, full of long islands and intricate channels with a lot of water wildlife. Near Carvoeiro the last major tributary of the Rio Negro, the
Branco River joins the Rio Negro and the river temporarily forms the border between the state of
Roraima and
Amazonas State, Brazil. The river now takes a more southeastern course, becoming again very wide in many stretches before reaching the biggest city on its course
Manaus. The
Anavilhanas National Park, a conservation unit that was originally an ecological station created in 1981, protects part of the Anavilhanas river archipelago in this part of the river. Below the archipelago, it meets the
Solimões River to form the
Amazon River, creating a phenomenon known as the
Meeting of Waters.
Major tributaries List of the major tributaries of the Rio Negro (from the mouth upwards) ==Discharge==