In 1926, a young couple set out into the British Columbia wilderness in search of an undiscovered mountain – taller than any peak in the Canadian Rockies – that experts said didn’t exist.

Their epic journey is now the subject of a new feature documentary, The Mystery Mountain Project, that’s having its festival premier at London Mountain Film Festival kicking off May 15, 2021.

Shot in B.C.’s remote Homathko valley, the film tells the story of North America’s original extreme sports couple, Don and Phyl Munday, husband and wife mountaineers, naturalists and explorers. In an age when women were expected to take care of the home, the couple set out as equals in the wilderness.

The Mundays were determined to find and climb an undiscovered peak they nicknamed Mystery Mountain. They believed it to be in the Coast range about 350 kilometers north of Vancouver, in an uncharted part of the province; a region of glaciers and frozen peaks that the Mundays bushwhacked into by compass and mapped by hand. Dodging grizzlies, quicksand, avalanches, rockslides, fighting off hunger and felling trees to cross swollen rivers — all the while hauling hundreds of pounds of food and gear.

Almost a century later, the film follows a group of amateur mountaineers as they set out to retrace the Mundays’ journey to Mystery Mountain — and climb it — using vintage 1920s gear. No Goretex jackets, no modern tents, no GPS or freeze dried meals. They soon discover they’ve bitten off more than they can chew. Lost and struggling through impenetrable brush, beset by injuries and personality clashes, it will take everything they’ve got to avoid disaster.

In the end, Don and Phyl proved the experts wrong. They not only found and mapped Mystery Mountain – now known as Mt Waddington, the highest mountain in British Columbia – but came back with photos as proof.

“For there to be a mountain of that size that most people didn’t even know existed, on the coast of British Columbia was a huge surprise in the early 1920s,” says Bryan Thompson, a Toronto history buff and the leader of the project, which was sponsored by the Royal Canadian Geographical Society.