Missouri River: Shonkin Sag near Highwood a channel eroded by the Missouri River. Cascade County, Montana. 1920.
Dates
Date Taken
1920
Summary
Missouri River: Shonkin Sag near Highwood a channel eroded by the Missouri River about the north base of the Highwood Mountains when temporarily diverted by the Keewatin ice sheet, now traversed by the Chicago, Milwaukee, St. Paul Railway. This part is 200 to 300 feet deep. Cascade Montana. September 16, 1920. Plate 30-A, U.S. Geological Survey Professional paper 174. 1932.
Summary
Missouri River: Shonkin Sag near Highwood a channel eroded by the Missouri River about the north base of the Highwood Mountains when temporarily diverted by the Keewatin ice sheet, now traversed by the Chicago, Milwaukee, St. Paul Railway. This part is 200 to 300 feet deep. Cascade Montana. September 16, 1920. Plate 30-A, U.S. Geological Survey Professional paper 174. 1932.
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