Ucayali

Ucayali, a river of Peru, one of the head-waters of the Amazon, is formed by the confluence of the Aprimac and Urubamba, and winds more than 1200 miles north to join the Marañon opposite Nauta. It traverses a rich, heavily wooded country, of great heat and moisture, and very unhealthy: enormous areas are flooded during the rainy season. It is navigable for large vessels as high as Sarayacu (6° 30' S.).