This report is based on field work of the season of 1897. It is designed mainly to furnish information in relation to the geologic structure and the prospects for underground waters. A general account will also be given of the surface waters and their present and prospective use for irrigation, etc. The region is the portion of Nebraska lying west of the one hundred and third meridian, comprising Sioux, Scotts Bluff, Banner, and Kimball counties, the western portions of Cheyenne and Boxbutte counties, and the central and western portion of Dawes County; in all, an area of 7,400 square miles, adjoined on the west by Wyoming, on the north by South Dakota, and on the south by Colorado. It lies on the Great Plains south of the Black Hills of South Dakota. The Scotts Bluff, Banner, and Cheyenne counties areas were· examined in detail, but time did not permit more than a general reconnaissance of the adjoining regions. I was assisted by Mr. C. A. Fisher, who obtained the data for the greater part of Kimball and Boxbutte counties. For several months I was accompanied by Prof. E. H. Barbour, the acting State geologist of Nebraska, who did much to further the progress of the work.
