North America's most spectacular mountains, the Teton Range, rise dramatically above a broad valley near the headwaters of the Snake River, immediately south of Yellowstone National Park. Culminating in Grand Teton, the highest peak at 13 770ft, these mountains extend from south to north and are the highlight of Grand Teton National Park, an area of 485sq mi of rugged peaks, alpine lakes, marshland and sage-and-aspen plains.