Book excerpt: In March 1990, Will Steger completed what no man had ever before attempted: the crossing of Antarctica, a total of 3,700 miles, on foot. Lured by the challenge and the beauty of Earth's last great wilderness, and determined to focus the world's attention on the frozen continent now that its ecological future hangs in the balance, Steger and his International Trans–Arctica team performed an extraordinary feat of endurance.