Guy Clarkson takes off in his bush plane, a Piper Super Cub on a four-hour filmic journey along the great Divide. The Blackfoot Indians call it "Mistakis", the "Backbone of the World". Clarkson feels expecially responsible for two thousand kilometres of the Rocky Mountains, from Yellowstone National Park in the south to the Yukon in the north. For over twenty-five years he's lived and worked here as a mountain guide, pilot and cinematographer. Always curious and ever respectful of the forces of nature we do not always understand, Clarkson is determined to come to grips with what makes his mountains work--and why he fears they might one day soon go on strike. He first examines The Ancient Ones, the rock and ice and flora and fauna that, over eons, have adjusted without complaint to every fluctuation in the natural order of things. Then came the first human inhabitants to the mountains, bands of nomads who survived by adapting to every change. Ice Ages and volcanic eruptions challenged but did not destroy them. But since the arrival of Europeans, the damage to ecosystems and tribes alike has approached a point of no return. From the glaciers of the Columbia Ice Fields, to the wolf packs of Yellowstone National Park, to the sacred hunting grounds of the Blackfoot nations, Clarkson finds perspective in the wisdom of the experts and elders who know this region best.