U.S. expedition kayaking extraordinaires Ben Stookesberry and Chris Korbulic, along with Brazilian heavy-hitter Pedro Oliva, a member of the first attempted descent of the Rio Mambucaba, document their recent paddling and canyoneering descent of this stout jungle river tucked away from the twin megalopolis population centers of Southeastern Brazil. The steep section of the Mambucaba, high in the Serra da Bocaina between São Paulo and Rio de Janeiro, dealt out roughly 4,000 feet of gradient in 20 miles that provided the expert crew a few challenges, to say the least. Here, Stookesberry breaks down the challenges of the expedition and provides seamless play-by-play commentary of how the group handled every challenge the rocks, river and jungle could deal to mark the first complete descent. CLICK HERE to view a gallery and to read more about the trip. Photos: Korbulic / Video: Stookesberry