Bulletin No. 22. The Geology and Water Resources of Northwestern Minnesota

This bulletin presents the results of an investigation of the geology and water supply of northwestern Minnesota. The area treated, as shown in Figure 1, page 2, comprises parts or all of twenty-six counties, for the most part west and north of St. Cloud; it includes about 28,725 square miles, or approximately one-third of the state. Field work was begun in 1924 and continued through three successive field seasons. The writer was assisted in the field during the entire season of 1924 by Mr. W. A. P. Graham, and for several weeks each by Messrs. G. A. Thiel and Francis Pettijohn. Subsequent field work was conducted by the writer alone. The field study consisted of inspection of wells, examination of materials from wells, collection of samples of water for analysis in the laboratory, interrogating well drillers, and gathering well logs and information regarding subsurface conditions. Samples of water for analysis were forwarded in glass-stoppered bottles of two-liter capacity to the laboratory at the University of Minnesota in Minneapolis, where the analyses were made immediately. All the analyses were made under uniform con- ditions by Dr. R. J. Leonard, of whose work the author wishes to express his appreciation