Quake Lake is on the Madison River, and is located just outside the northwest boundary of Yellowstone National Park. Like Yellowstone, the area is on a fault zone and experiences hundreds of quakes a year. In September, 1959, an extra large quake hit the area, causing an avalanche of rocks that filled the canyon and splashed part-way up the canyon wall on the far side. The Madison River was effectively blocked, and dried up for miles down stream.
Here is where the avalanche originated:
And here are some of the rocks that were forced up the canyon wall on the far side. The large boulder on top is about 20 feet high.
As the water backed up behind the new quake-made dam, geologists and engineers worried that once the water reached the top, it would cause part of the new dam to crumble and result in flooding below. So the US Army Corps of Engineers brought in huge earth-moving equipment and created a channel for the water. The Madison River flows again, and continues to work away at the channel, making it deeper and wider.
Flat areas, like the area in the photo below where the single tree stands, were created by the bull dozers 50 years ago:
The lake is slowly emptying. In a few hundred years, the lake will disappear and the Madison River will once again flow freely through the canyon.
The forces of nature at work, on a constantly changing earth.
