There is plenty of evidence that the sea flooded the interior of continents in Earth history. About 12,000 years ago, the valleys of Western Montana lay underneath a lake nearly 2,000 feet deep. It was then when the failure occurred. The water pressure caused the glacier to become resilient and the water began to escape under the ice dam. Water reached a maximum height at an elevation of 4,200 feet that debilitated the glacial block until water burst through in a devastating flood that raced across Idaho, Oregon and Washington. Huge waves and pieces of ice ripped away soils and mountainsides, deposited massive ripple marks and carved the Columbia River Gorge. At that point, Glacial Lake Missoula was as big as Lakes Erie and Ontario combined and the flood waters ran with the force equal to sixty Amazon Rivers.

Harlen Bretz and Joseph T. Pardee were the two geologists that studied this event to find the causes of the features in eastern Washington. They realized that these features must have been formed by enormous scale flooding of devastating proportion. It took several years for the geologic community to accept their interpretation but thanks to the clues to the puzzle provided by these two geologists we have been able to discover one of the most unbelievable events in history.

References:

• Robbins, J. (2014, August 24). Ice Age Floodwaters Leave a Walkable Trail Across the Northwest. Retrieved from http://www.nytimes.com/learning/teachers/featured_articles/20040824tuesday.html
• United States. National Park Service. (n.d.). Ice Age Floods Alternatives Study: Final Report. Retrieved April 10, 2016, from https://www.nps.gov/iceagefloods
• Glacial Lake Missoula and the Ice Age Floods. (n.d.). Retrieved April 10, 2016, from http://www.glaciallakemissoula.org/