RED LODGE POST
A window to Pleistocene history Glacier National Park, Montana, c 12000 years ago.
A massive alpine glacier fills McDonald Valley, Glacier National Park, Montana. Photo from a GNP Web cam at Apgar Mountain, September 28, 2020, 7:30 a.m.
Beautiful glacial Lake McDonald in McDonald Valley, Glacier National Park, as it appeared on September 9, 2020, 1:13 p.m. Photo from a GNP Web cam at Apgar Mountain.
Mystery unraveled:
In the first photo, nature revisits the geologic past. A giant cloud hovers over current Lake McDonald and the McDonald Valley, below the surrounding mountain peaks, simulating how the valley may have appeared c 12000 years ago when the valley was filled by an alpine glacier.
Glaciers are a cyclical phenomenon of the recent geologic past in North America. The present time is likely an inter-glacial period. This suggests that massive alpine glaciers will cover much of the northern Rocky Mountains in North America, including Glacier National Park, again in the future.
Absaroka Mountain, Mont.
© 2021 John Sandy