Born of the Ice, Yosemite Is a Climber's Mecca

In Born of the Ice, Yosemite Is a Climber's Mecca, geologist Iain Stewart describes how the mountains in Yosemite were carved out by glaciers over tens of thousands of years, leaving behind boulders and waterfalls — remnants of ancient rivers. El Capitan, rising up from the valley floor, challenges climbers with its towering, vertical rock face. This video is excerpted from BBC’s Earth: The Power of the Planet, a documentary series in which Dr. Iain Stewart discovers how Earth's forces can shape nature, species, and even the climate.