Breukelman (1940) and Jennings (1942) listed fishes from the University of Kansas Museum of Natural History and the Kansas State College Museum, respectively, including some specimens collected from the Big Blue River System in Kansas. Because records in these two papers pertain to collections that were widely spaced in the basin and in time, the specific localities are not given herein. One of Jennings' (_loc. cit.)_ records, _Scaphirhynchus platorynchus_ (Rafinesque), was cited by Bailey and Cross (1954:191). More recently, Minckley and Cross (in press) recorded several localities, and cited some papers mentioned above, in a publication dealing with _Notropis topeka_ (Gilbert) in Kansas. Information on the fishes of the Nebraskan portion of the Big Blue River Basin was compiled, and additional localities were reported, in a doctoral thesis by Dr. Raymond E. Johnson, entitled The Distribution of Nebraska Fishes, 1942, at the University of Michigan. METHODS AND MATERIALS _Collection of Fishes_ The gear and techniques used are listed below: ENTRAPMENT DEVICES.--Hoop and fyke nets and wire traps were used for 288 trap/net hours in 1957. The nets were not baited, and were set parallel to the current, with the mouths downstream. Hoop nets were 11/2 to three feet in diameter at the first hoop, with a pot-mesh of one inch; fyke nets were three feet at the first hoop, pot-mesh of one inch; wire traps, with an opening at each end, were 21/2 feet in diameter and covered with one-inch-mesh, galvanized chicken wire. GILL NETS.--Experimental gill nets were set on three occasions in areas with little current. These nets were 125 feet in length, with 3/4 to two inch bar-mesh in 25-foot sections. SEINES.--Seining was used more than other methods. An attempt was made to seine all habitats at each station. In swift water, seine-hauls were usually made downstream, but in quiet areas seining was done randomly. Haul-seines six to 60 feet in length, three to eight feet in depth, and with meshes of 1/8 to 1/2 inch were used. For collection of riffle-fishes, the seine was planted below a selected area and the bottom was kicked violently by one member of the party, while one or two persons held the seine, raising it when the area had been thoroughly disturbed. Seining on riffles was done with a four-foot by four-foot bobbinet seine. ROTENONE.--Rotenone was used in pools of smaller streams, mouths of creeks, borrow-pits, and cut-off areas. Both powdered and emulsifiable rotenone were used. The rotenone was mixed with water and applied by hand, or into the backwash of an outboard motor. ELECTRIC SHOCKER.--The electrical unit used in this study generated 115 volts and 600 to 700 watts, alternating current. The shocking unit consisted of two booms, each with two electrodes, mounted on and operated from a slowly moving boat. Fish were recovered in scape nets, or in many cases were identified as they lay stunned and were not collected.