A century ago, the first expedition to attempt a summit of Mount Everest had to undertake a massive 360-mile trek from India to Tibet, just to reach the mountain itself. On that arduous journey, Canadian Oliver Wheeler, was brought along to map the Everest region.

Author and explorer, Wade Davis, became fascinated with one of the most courageous and intriguing Canadians that few Canadians have ever heard of, and uncovered an incredible story when he tracked down Wheeler’s son and the handwritten journals in which the mountaineer had recorded his trials and triumphs on the 1921 Everest expedition.

Watch Wheeler’s Everest.