In 1947, former OSS agent, retired US Army Colonel, and explorer Leonard Clark, came into possession of a secret map that led him to 7 ancient cities of gold deep in the Amazon jungle of Peru. Despite being chronicled in his book The Rivers Ran East, few people have attempted to confirm his discovery. Until 2013.

The River's Ran East project follows the journey of seven individuals who retraced Leonard Clark’s route along the Marañón River in Northern Peru to confirm his claims, attempt to locate the ancient ruins, and learn about the rich history, ecosystems, and cultures of the area. It is a story about understanding the past, and improving the future. It is about the corners of this world where people and the environment still depend on each other, and is about the threats that these communities face from illegal loggers and miners.

In June of 1946, former OSS officer Colonel Leonard Clark arrived in Lima, Peru with $1000 – all that he owned – pinned inside his shirt pocket. His goal: to discover the gold of the legendary city of El Dorado and the Seven Cities of Cibola. Clark recounts the tale of having received a tattered and incomplete 500-year-old map from a friend in Lima that had been passed down through generations from the sole survivor of a jungle massacre in the early 1500's. Clark arrived in South America with only a brief note of introduction to a Peruvian that claimed to know the gold’s location. Drawn by visions of El Dorado and a map that would lead him to it, Clark headed into the jungle with barely enough provisions to sustain him. Relying on his wartime experience in Asia, his travel companions, and his wits to see him through, Clark embarked on a journey of epic proportions. He sought solace through companionship in the redoubtable Jorge Mendoza, a twenty-four-year-old Peruvian graduate of Lima University, and the fearless Inez Pokorny, a mysterious, gutsy, and multilingual explorer.

Along their perilous journey, they encountered man-eating jaguars, forty-foot-long anacondas, poisonous plants, and treacherous conditions. On his journey, Clark documented the local flora and fauna, the function and applications of medicinal herbs from Indigenous healers, and descriptions of the many Tribes and their languages. Remarkably, after nine months in the jungle, Clark emerged over the high Andes leading a mule with $16,000 in gold dust strapped to its back. Long out of print, the River's Ran East was originally published in 1953. Available today as part of the Travelers’ Tales Classics series, this tale remains one of the greatest journeys ever recorded. Most importantly, the story isn't over. The River's Ran East team is preparing to return in the next few years, so stay tuned.