This fascinating book tells two separate stories separated by 14,000 years.
The first is that of the repeated waves of awesome Ice Age floods -- the greatest known to have occurred anywhere in North America -- which swept across the face of eastern Washington, down the Columbia Gorge, and up the Willamette and Tualatin valleys, catastrophically changing the face of thousands of square miles of the Pacific Northwest.
The second is that of J Harlen Bretz, a remarkable geologist who defied the scientific orthodoxy of his day and argued that sudden floods of almost unimaginable force rather than the slow, uniform processes of erosion had created the scablands of eastern Washington. Bretz lived to the great age of 98, and in his later years he had the satisfaction of seeing his theories vindicated.
Enormous ice-age lakes, with one-fifth the volume of Lake Michigan, repeatedly grew behind dams of ice in northern Idaho and Montana. When the rising waters became deep enough to float the ice, they lifted the dam and the ice was swept away. Hundreds of cubic miles of lake water rushed southwest at speeds of up to 50 miles per hour, carrying away deep loess soils and leaving in their wake the scarred land and deeply cut valleys which are such striking features of the Washington scablands.
Farther west, the floods crested at 1000 feet entering the Columbia Gorge, and spread out in the Portland basin to a depth of 400 feet, eventually leaving such landmarks as Rocky Butte, the Tualatin scablands, Lake Oswego, and the erratic boulders strewn throughout the Willamette Valley. Perhaps most amazing, the ice continued to dam a new lake, and the whole process was repeated every 50 years or so for 2000 years!
Cataclysms on the Columbia is a gripping account of the extraordinary natural forces that shape the familiar features of the Northwest. The book concludes with descriptions of the evidence of the floods that can be seen in the landscape guide for the interested traveller. Maps, highway directions, and many photos make it easy for the amateur geologist to rediscover the clues which led J Harlen Bretz to his monumental discovery.
John Eliot Allen, Professor Emeritus of Geology at Portland State University, is a lifelong student of the Columbia Gorge and the author of The Magnificent Gateway, a detailed guide to its geology. Marjorie Burns is Professor of English at Portland State University and a frequent contributor to various journals. Sam Sargent was the chief geologist in the building of the Dalles Dam.