This scarce map was prepared to illustrate David D. Owen's report. An early geological survey of the area between Prairie du Chien (here Fort Crawford and Kipy Saging) and north along the Mississippi River to the Minneapolis area and further north beyond Duluth. Extends east to include the rapids along the northern reaches of the Wisconsin River. A legend in the lower right explains the use of color to indicate the twelve different geological formations.

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Condition: A

Good impression and fine original coloring. Issued folding, now backed with archival tissue. A little light toning along some folds and some insignificant spots, still very good for a map of this size.