The Great Missoula Floods of the Last Ice Age

Document Type


Publication Date



The Missoula Floods of the last Ice Age in the Pacific Northwest were the largest freshwater floods yet known on the surface of the Earth. The flood-formed landscape is a spectacular example of the power of geologic processes. But the Missoula Floods are also a story of controversy: an example of dogma and personality obscuring and facilitating the quest for truth. This is science in action, not always pretty, but continuously motivated by the wonderment of discovery.

Streaming Media


Jim O’Connor is a Research Geologist at the U.S. Geological Survey in Portland, Oregon. He majored in Geological Science at University of Washington and earned M.S. and Ph.D. degrees at University of Arizona. Since 1991, he has worked at the U.S. Geological Survey, intent on improving understanding of the remark-able and diverse landscapes of our planet.