The largest unit in the entire National Park System at over 13 million acres — larger than California — Wrangell-St. Elias contains more than all other national parks combined, including 9 of the 16 highest peaks in the United States and some of the world's largest non-polar glaciers. The abandoned Kennecott copper mine, which produced $200 million worth of ore between 1903 and 1938, is the preserve's most visited human landmark, accessible by a 60-mile unpaved road.