In 1914, President Theodore Roosevelt descended an unexplored, rapids-filled tributary of the Amazon. He almost died in the process and the legendary "River of Doubt" was renamed the Rio Roosevelt. One hundred years later, it remains a remote and relatively untraveled tributary of the Amazon. In June 2014, my paddling partner, Paul Schurke and I found ourselves camped on the edge of the river where Roosevelt’s party had lowered their two-ton dugout canoes into the swollen river and began their epic descent.

On February 27, 1914, shortly after midday, we started down the River of Doubt into the unknown. We were quite uncertain whether after a week we should find ourselves in the Gy-Parana, or after six weeks in the Madeira, or after three months we knew not where. That was why the river was rightly christened the Duvida. – Theodore Roosevelt

The stars leapt out of the black, moonless sky and I could feel the stress subside and excitement grow. In the morning we would load our canoe and paddle around the first bend in the river just like Roosevelt. Alone in the darkness I suddenly felt vulnerable and turned on my headlamp. Yellow eyes shown back and I could make out the large cat’s long tail as it disappeared into the thick vegetation 25 paces from me, our eyes locked the whole time. I slowly walked backwards towards our camp, eyes glued on the glowing eyes in the bushes. My body surged with adrenaline from seeing my first jaguar. There is something about being alone in the dark with a large predator that makes you feel like prey.

The first 45 miles of river were fast flowing, but contained no rapids. A steady current pushed us downstream. Macaws cried overhead and the stench of hundreds of white-lipped peccaries permeated the air. Giant river otters bobbed up and down, snorting as we paddled by. After two days of easy paddling, the dull roar of rapids appeared and our focus shifted to the obstacles ahead. The river’s character quickly changed, rapids that pummeled Roosevelt’s canoes and pushed his team to the brink of starvation would test our skills as well. It took Roosevelt’s team 3 days to haul their 1-ton dugout canoes around the first mile long rapids, but it took us only an hour. At the bottom of the gorge we found the same amazing geologic phenomena that Roosevelt had marveled at in his diary. The river, which is about 30 yards wide above the gorge, funnels down and exits the gorge through a seemingly bottomless slot canyon that’s just 4 feet wide. This was the river we had read about in Roosevelt’s journals and had come to explore. Over the next 450 miles over 60 rapids interrupt the Rio Roosevelt. We would spend 35 days on the river, navigating the rapids and hacking portage trails through the dense jungle. With modern equipment and satellite images of the numerous rapids and falls it was an epic adventure, which I would repeat in a heartbeat. What kept me up at night was the thought of Roosevelt and his men descending the river in dugout canoes and no clue where the river was going, or what obstacles lay in their path. In the years following his journey, Roosevelt shared the story of his epic adventure and the new river he had charted at speaking engagements across the US and Europe. But his family & friends could see that the rigors of the journey had taken a toll on him. By his own reckoning, written in a letter a month before he died Roosevelt said, “Nobody ever packed more varieties of fun and interest in 60 years.” View a gallery of the River of Doubt expedition here.

National Geographic Adventurers of the year, Dave and Amy Freeman, are currently on a 100 day, 2,000 mile journey from Ely, Minnesota to Washington DC. They are paddling a petition canoe to help protect the Boundary Waters Canoe Area Wilderness from several sulfide ore mines, which threaten the pristine lakes and rivers of America's most popular wilderness area. You can help protect the Boundary Waters by signing their petition and learn more about their current journey at www.PaddletoDC.org. They also sent us a note about their Goal Zero gear: "Whether we are in the field for a few days, or a few months we rely on Goal Zero solar panels and battery packs to power our cameras, GPS, and other electronics. We have been communicating with tens of thousands of school children during expeditions to some of the most remote corners of the planet for the past 15 years, and powering our communication equipment was one of our biggest challenges. Goal Zero’s rugged, thoughtfully designed equipment has made it a snap."