Fifteen miles to the south-east of Denali, the highest peak in North America, lies a colossal mountain range that rears from the ground like a vertiginous jaw. Fittingly, the various summits of this natural wonder are called Moose’s Tooth, Eye Tooth, Sugar Tooth and Broken Tooth. While many explorers have conquered each of these peaks, none have attempted a lateral climb from summit to summit,akin to walking atop the skyline. But a black-and-white aerial photograph of the forbidding path, all snow-capped and wrapped in billowy clouds, beckons the adventurous spirit of mountaineers Renan Ozturk, Freddie Wilkinson and Zach Smith.

Directed by Ozturk and Wilkinson, this awe-inspiring documentary is as much about their years-long attempts to scale the Tooth traverse as it is about Brad Washburn, the man behind the image that ignited their curiosity. A daring figure with an inexhaustible passion for exploration, Washburn pioneered the use of aerial photography in cartography, crafting superbly detailed maps of regions previously neglected by geographers. The extraordinary milestones of Washburn’s career – including his tenure as the director of the Boston Museum of Science – are interwoven with the highs and lows in the three climbers’ private lives. Despite the deaths of fellow mountaineers, neck-breaking accidents and financial struggles, their determination to scale the traverse is staggering in its unshakeable resilience. And amid perilous risks of avalanche and falling rocks, their enthusiasm has a childlike wonder that feels especially moving.

While the juxtaposition of different timelines results in occasional clunkiness, the breathtaking cinematography more than makes up for the uneven telling. In the face of global climate change, these images of the glacial otherworldliness of Alaska carry a wistful splendour and a bittersweet urgency.

• The Sanctity of Space is released on 4 March in cinemas.