Great Missoula Flood - Scablands And Plunge Pools

  During the last ice age, a lobe of the ice sheet covering western Canada dammed the Clark Fork River, creating a vast lake in what is now northwestern Montana. Several times during the past 15,000 years, the ice dam broke, sending hundreds of cubic miles of water roaring across the inland Northwest and down the Columbia River Gorge. It left 100-ton boulders scattered across the land, gorges 1000 feet deep, and enormous potholes. Now on a quiet, sunny October day, Mallards (like this female), pintails, and Gadwalls bathe and preen in a pool created by one of the greatest floods the Earth has ever known.