_Marais des Cygnes River, Upper Station._--One mile south and one mile west of Pomona, Franklin County, Kansas (Sec. 12, T. 17 S., R. 17 E.) (Pl. 27, Fig. 1). Width 30 to 40 feet, depth to six feet, length of study-area one-half mile (three large pools with short connecting riffles), bottom of mud and bedrock. Mud banks 30 to 40 feet high. According to P. Lindsey (landowner) this section of the river was intermittent for most of the drought. Flow was continuous in 1957, 1958 and 1959. There are four low-head dams between the upper and middle Marais des Cygnes stations. _Marais des Cygnes River, Middle Station._--One mile east of Ottawa, Franklin County, Kansas (Sec. 6, T. 17 S., R. 20 E.) (Pl. 27, Fig. 2). Width 50 to 60 feet, depth to eight feet, length of study-area one-half mile (one large pool plus a long riffle interrupted by several small pools), bottom of mud, gravel, and rock. Mud and sand banks 30 to 40 feet high. This section of the river was intermittent for much of the drought. In the winter of 1957-'58 a bridge was constructed over this station as a part of Interstate Highway 35. Because of this construction many trees were removed from the stream-banks, the channel was straightened, a gravel-bottomed riffle was rerouted, and silt was deposited in a gravel-bottom pool. _Marais des Cygnes River, Lower Station._--At eastern edge of Marais des Cygnes Wildlife Refuge, Linn County, Kansas (Sec. 9, T. 21 S., R. 25 E.). Width 80 to 100 feet, depth to eight feet, length of study-area one-half mile (one large pool plus a long riffle interrupted by several small pools), bottom of mud, gravel, and rock. Mud banks 40 to 50 feet high. This section of the river ceased to flow only briefly in 1956. METHODS _Electrical Fishing Gear_