Lower Two Medicine Lake, Glacier National Park, Montana, USA.
Lower Two Medicine Lake reflects peaks in Glacier National Park, Montana, USA. Since 1932, Canada and USA have shared Waterton-Glacier International Peace Park, which UNESCO declared a World Heritage Site (1995) containing two Biosphere Reserves (1976). Rocks in the park are primarily sedimentary layers deposited in shallow seas over 1.6 billion to 800 million years ago. During the tectonic formation of the Rocky Mountains 170 million years ago, the Lewis Overthrust displaced these old rocks over newer Cretaceous age rocks. Glaciers carved spectacular U-shaped valleys and pyramidal peaks as recently as the Last Glacial Maximum (the last "Ice Age" 25,000 to 13,000 years ago). Of the 150 glaciers existing in the mid 1800s, only 25 active glaciers remain in the park as of 2010, and all may disappear by 2020, say climate scientists.Add to Cart Add to Lightbox Download