Rote to Lapwai along the south side of the Clearwater. No silts or other evidences of glacial waters seen in the canyon followed by the road out of the eastern part of Lewiston. Climb reaches 1650 approximately. No silt or other features of this sort in the lower valley of Lapwai Creek, which was entered at the town of Lapwai. Bretz Field Notes
A terse line from a survey notebook, and the flood evidence it set down.
Today we know the Purcell Trench ice lobe created an ice dam roughly 2,000 feet tall at this latitude. The dam formed and broke repeatedly over 2,000 years, producing as many as 80 separate catastrophic floods.
Active: 1914-1979 (primary IAF fieldwork 1922-1932; Penrose Medal 1979) Affiliation: University of Chicago (Instructor 1914, Professor 1926, retired 1947, emeritus through 1979) Key paper: Bretz, J H. (1923). "The Channeled Scabland of the Columbia Plateau." Journal of Geology 31(8): 617-649.
Bretz spent seven summer field seasons beginning in 1922 walking the basalt coulees, dry cataracts, and giant gravel bars of eastern Washington and concluded that the landscape required a catastrophic flood at a scale no existing process could produce. He coined the term "Channeled Scabland" in his 1923 paper and over the next decade defended the hypothesis against a uniformitarian geology establishment that had no plausible source for the water and viewed catastrophism as scientifically illegitimate. Bretz refused to name a source until Pardee's 1942 paper supplied one: Glacial Lake Missoula. He continued publishing on the scablands as an emeritus professor through the 1950s and 1960s, including his synthesis "Washington's Channeled Scabland" (1959). The Geological Society of America awarded him the Penrose Medal in 1979 at age 96; he reportedly remarked to his son, "All my enemies are dead, so I have no one to gloat over."
Source: J Harlen Bretz - Wikipedia; HistoryLink.org; University of Chicago Magazine
Flood-extent overlay shows the maximum reach of the Missoula Floods.
One of more than 1,800 surveyed sites. Plotted together, the field record is the map that proved the flood.
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