The
Pastaza (the ancient river Sumatara) is a large
tributary to the
Amazon River. It rises on the
Ecuadorian tableland, where a branch from the valley of
Riobamba[?] unites with one from the
Latacunga[?] basin and breaks through the inland range of the
Andes; and joined, afterwards, by several important tributaries, finds its way south-east among the gorges; thence it turns southward into the plains, and enters the Amazon at a point about 60 miles west of the mouth of the
Huallaga. So far as known, it is a stream of no value except for canoe navigation. Its rise and fall are rapid and uncertain, and it is shallow and full of sandbanks
and snags. It is a terrible river when in flood.