Putumayo or Icá river, which means "river that rises where plants grow whose fruits are used as vessels". It is a long Amazonian river that rises in the Colombian Massif and flows into the Solimoes River. It has a length of 1813 km and drains a basin of 148,000 km. Its main tributaries are the Guamúez (140 km), San Miguel (240 km) and Igara Paraná (440 km) rivers. It is an important waterway, as it is navigable almost all the way.