My colleague, the late great Loren McIntyre, discoverer of the source  lake of the Amazon, Laguna McIntyre in the Peruvian Andes, was lost on the Peru-Brazil border about 30 years ago.
Meu grande colega, já falecido, Loren McIntyre, que descobriu a nascente do rio Amazonas, Laguna McIntyre nos Andes peruanos, se perdeu na fronteira Peru-Brasil  30 anos atrás.