The Khumbu glacier twists and winds it way down Everest’s southern flank. As this massive river of ice reaches a set of cliffs above base camp, it spills over the edge where towering pillars and massive blocks of ice are frozen in their slow-motion fall. Climbers on the South Col route use a series of ladders and ropes to ascend through this hazard. The shifting glacier needs daily attention and this is where the Khumbu Ice Doctors work to modify the route as the pillars shift and collapse on a daily basis. This team of specialized Sherpas spend the season keeping the route to camp one open and every expedition depends on their work.