After joining the Mantaro River, the ApurImac becomes the Ene; after joining the PerenE River, it becomes the Tambo.
The headwaters of the ApurImac, which rise from glacial meltwater on Nevado Mismi, were determined by a 2000 expedition to the most distant from the mouth of the Amazon.
The major headstreams of the Amazon are the Ucayali and Marañón rivers, both of which rise in the permanent snows and glaciers of the high Andes Mountains.
Feeding the Ucayali is the Apurimac River, the Amazon's most distant source.
The headwaters of the Apurimac are located at a glacial meltwater of Nevado Mismi, an Andean peak in southern Peru.