<P> The headwaters of the Apurímac River on Nevado Mismi had been considered for nearly a century as the Amazon 's most distant source , until a 2014 study found it to be the Cordillera Rumi Cruz at the headwaters of the Mantaro River in Peru . The Mantaro and Apurímac confluence , and with other tributaries form the Ucayali River , which in turn confluences with the Marañón River upstream of Iquitos , Peru , to form what countries other than Brazil consider to be the main stem of the Amazon . Brazilians call this section the Solimões River above its confluence with the Rio Negro to form what Brazilians call the Amazon at the Meeting of Waters ( Portuguese : Encontro das Águas ) at Manaus , the river 's largest city . </P>
where does the source of the amazon river start
the Cordillera Rumi Cruz at the headwaters of the Mantaro River in Peru