The Alaska Range is a 600-mile long arc of mountains that stretches from the Alaska-Canada border all the way to the Alaska Peninsula. The range is highest at its mid-section, a vast region of towering peaks and massive glaciers that lies within Denali National Park and Preserve. Denali is a region of great geologic activity and complex-ity, and scientists are only beginning to piece together its puzzling past. It has rock for-mations that have been carried there from thousands of miles away, fossils of ancient creatures that have been plowed up from ocean depths, new rocks born of the Earth’s internal fire, and some of the oldest rocks in Alaska. The range’s height and distance from the equator combine to make it a place of eternal winter, and deep snows com-press to form glaciers (creeping rivers of ice which continuously grind away at the still-rising peaks). It would be considered one of the world’s great geologic showcases even if it didn’t contain the highest peak in North America.