The Big Blue River in northeastern Kansas will soon be impounded by the Tuttle Creek Dam, located about five miles north of Manhattan, Kansas. Since the inception of this project by the U. S. Army Corps of Engineers much argument has arisen as to the values of the dam and reservoir as opposed to the values of farmland and cultural establishments to be inundated (Schoewe, 1953; Monfort, 1956; and Van Orman, 1956). Also, there has been some concern about the possible effects of impoundment on the fish-resources of the area, which supports "a catfish fishery that is notable throughout most of the State of Kansas and in some neighboring states (U. S. Fish and Wildlife Service, 1953:9)." The objectives of my study, conducted from March 30, 1957, to August 9, 1958, were to record the species of fish present and their relative abundance in the stream system, and to obtain a measure of angler success prior to closure of the dam. These data may be used as a basis for future studies on the fish and fishing in the Big Blue River Basin, Kansas. ACKNOWLEDGMENTS I thank Messrs. J. E. Deacon, D. A. Distler, Wallace Ferrel, D. L. Hoyt, F. E. Maendele, C. O. Minckley, B. C. Nelson, and J. C. Tash for assistance in the field and for valuable suggestions. Dr. J. B. Elder, Kansas State College, arranged for loan of specimens, and Mr. B. C. Nelson supplied data on _Notropis deliciosus_ (Girard) in Kansas, and on specimens in the University of Michigan Museum of Zoology. I thank the many landowners who allowed me access to streams in the Big Blue River Basin. The U. S. Army Corps of Engineers, Kansas City District, also allowed access in the reservoir area, and furnished information and some photographs. Mr. J. C. Tash did chemical determinations on my water samples. Dr. Frank B. Cross guided me in this study and in preparation of this report. Drs. E. Raymond Hall and K. B. Armitage offered valuable suggestions on the manuscript. Equipment and funds for my study were furnished by the State Biological Survey of Kansas, and the Kansas Forestry, Fish and Game Commission granted necessary permits. TUTTLE CREEK DAM AND RESERVOIR The data on Tuttle Creek Dam and Reservoir that follow were furnished by Mr. Donald D. Poole, U. S. Army Corps of Engineers, Kansas City District. The dam, an earth-fill structure, will be 7,500 feet in length, with a maximum height of 157 feet above the valley floor. Release of water will be from beneath the west end of the dam, through two tunnels 20 feet in diameter that have a capacity of 45,000 cubic feet per second; however, releases exceeding 25,000 c. f. s. are not planned. The gated spillway is located at the east end of the dam. Freeboard will be 23 feet at the top of flood-control pool.