It has granitic plutons (large plugs of granitic rock welling up from the mantle), indicating an Archean subduction zone. That means the core of the Wind River Range is nearly 4 billion years old! Whoo!
The range runs roughly NW-SE for over 100 miles. The Continental Divide is parallel to the range, making this one of the most unique mountain ranges in the US.
With the exception of the Grand Teton in the Teton Range, the next 19 highest peaks in Wyoming are also in the Wind Rivers.
Ice Ages beginning 500,000 years ago carved the granite into their present shapes (geomorphology). Lakes were formed by the glaciers and numerous cirques (circular valleys made by glacial ice), were carved out of the rocks, the most well known being the Cirque of the Towers (if you've ever seen a postcard of Wyoming with a glacier and a jagged peak, its probably of the Towers). Several of these are some of the largest glaciers in the U.S. Rocky Mountains. Gannett Glacier, which flows down the north slope of Gannett Peak, is the largest single glacier in the Rocky Mountains.
|The Wind River Range is in pink (picture from Wikipedia Commons).|
We'll talk about Plate Tectonics another time. :)