Rio Marañon: Expedition to the Grand Canyon of the Amazon


LaceyExpedition rafter Lacey Anderson checks in while preparing for her biggest trip ever, a mission to Peru’s Rio Marañon.


For many years now I’ve attempted to spend as much time as possible on rivers, seeking out extended wilderness journeys. I’m really excited about one particular multi-day trip coming up this fall. It will be the longest river expedition I’ve done to date—an entire month on the river.

A group of us will be spending 28 river days on the Rio Marañon in Peru. The expedition will start high in the Peruvian Andes at an elevation of around 7,000 ft and will end in the humid, tropical jungles at an elevation of about 1,000 feet. We’ll travel over 400 miles on this key tributary and hydrological source of the mighty Amazon. The canyon averages about 8,000 feet in depth on both sides for hundreds of miles. By the halfway point of our adventure we will have traversed a canyon that is deeper than the Grand Canyon, reaching a depth of nearly 10,000 feet in several places!

Rio Maranon Cacti

As we travel along the river, we will camp on untouched expansive white sand beaches, soak in soothing hot-springs, hike up narrow slot canyons, visit secluded grottos, witness amazing waterfalls, gaze at multi-colored cliffs soaring high above, and touch smooth, vertical limestone walls. We will be treated to rich colors reminiscent of the American Southwest; deep green riparian vegetation contrasted against dark red dirt, the mellow tans of sandstone, and the interesting black and white swirling geology of metamorphosed rock. There will be warm turquoise colored tributaries streaming out of flash-flood-chiseled side canyons. Wildlife in the region is exotic; creatures such as sloths, a variety of monkeys, and giant centipedes have been spotted along the river. Parrots and other colorful birds will soar among the cliffs, and piranha will swim in the lower reaches of the river. Ancient Incan ruins and indigenous villages are scattered throughout the canyon; we will be lead to Incan ruins (undiscovered by academia) by local residents and visit the indigenous Aguaruna people living in harmony with the jungle.

Rio Maranon Beach Camp

Historically the Rio Marañon river flow peaks beteen mid-March and mid-April with an average discharge of about 33,000 cfs. During the time of our trip, the historic average is around 8,000 cfs. With the onset of the rainy season, the flow during November historically doubles to about 16,000 cfs. This makes for exceptional whitewater through the entire year that is comparable to our own Grand Canyon of the Colorado, ranging from flat calm water to run-able Class V. In the 400-mile section from Puchka to Imacita, there are more than 150 Class II rapids, 83 Class III’s, 23 Class IV’s, and two Class V rapids to negotiate. Best of all, we will be exploring one of the most magnificent and last free flowing rivers of the world! When a river is not dammed, the glorious natural cycles are experienced and conditions can change quickly and dramatically. We will be prepared to cope with changes in the river should winter rains begin to fall early.

Rio Maranon Wasson's Landslide Rapid

Our journey down this mighty river will not be solely for pleasure and adventure, rather it is intended to increase awareness of, and appreciation for, this magnificent river. The Rio Marañon is under immediate threat and stands at the threshold of either destruction or preservation by mankind. There are around twenty dams proposed on the Rio Marañon, with three of them being mega-dams. One hydro dam after another is planned for the entire length of the Marañon which will leave little or no free-flowing river sections. The energy generated would be exported to other countries and enrich the builders of the dams and their foreign investors, not the people of Peru, and certainly not the thousands of local residents along the Rio Marañon. While there is fierce opposition to the dams by the residents along the river, the damming companies (and the government) are using underhanded tactics  to get the communities’ approval and push through their hydro projects. Residents are trying to organize and protest, but there are entities working against them. Also, misconceptions abound among the residents along the river, especially by the Awajún (Aguaruna) in the jungle areas. Although projects upstream will not directly affect them, solidarity is needed to prevent all the dams.

Rio Maranon Hotspring

By documenting the Marañon and the threats facing the river today, we hope to help garner support for opposition to the proposed dams, which would destroy the free-flowing nature of the upper Amazon. If these dams are built, there will be catastrophic environmental impacts; not only will sand and silt deposition patterns come to a stop, but fish and wildlife habitat will be destroyed. There will be devastating social impacts; thousands local residents and indigenous peoples will be displaced, losing their traditional way of living off of the verdant river lands and jungles. Historical and cultural impacts will be enormous; numerous archeological sites of the Incan and Chachapoyan cultures are found along the river and have yet to be excavated and studied. Finally, damming Rio Marañon will result in the loss of potential recreational and ecotourism opportunities. It is vitally important to raise awareness to this situation and amass as much opposition to the dams as possible, because two of the dams along the Marañon are in the late planning stages. Foreign companies intend to start construction as early as next year. For more information, see the July/August issue of American Whitewater or this write up from International Rivers.

Editor’s Note: Since writing this dispatch, Lacey and her boating partners completed their trip down the Rio Marañon. Lacey recently checked in with us from Lima, Peru, where she was preparing for another river expedition and writing. Watch for upcoming stories and about her experiences in the “Grand Canyon of the Amazon” and on Mexico’s Rio Sirupa.