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electrofishing jon boat powered by an outboard motor and the other a 4.5-m long, oar-powered electrofishing raft. The purpose was to "hunt" for and capture Colorado pikeminnow that had passed through the Redlands fish passageway and determine the extent of their movement upstream of this facility. The boat was equipped with a HondaO 5-kilowatt A.C. generator that powered a Coffelto model VVP-15 pulsator. The raft was equipped with a Vanguard@ 9-horsepower D.C. generator that powered a Smith-Root° model GPP 5.0 pulsator. Investigators used direct current and tried not to exceed 300 volts or 12 amps to minimize injury to fish, while maximizing electrofishing effectiveness. The boat used two stainless steel, spherical anodes (about 6.59-cm diameter) suspended from fiberglass booms in front and two 2.1-m cathodes (0.64-cm diameter twisted stainless steel cable) suspended from each side of the boat. The boat hull was also used as a cathode in conjunction with the droppers. The raft used one 8.5- cm stainless steel sphere for the anode off the bow of the raft and a number (about 12) of 0.64-cm stainless steel twisted cables for cathodes that were suspended off the stern of the raft. Electrofishing proceeded downstream in a continuous fashion from Delta to the Redlands Dam. The raft sampled mostly shoreline habitats whereas the motorized boat sampled all possible habitats, maneuvering into eddy habitats, fast current shorelines, and traveling upstream to sample areas that were difficult to access with the oar-powered raft. Two different size trap nets and two sizes of trammel nets were used to collect sub-adult and adult Colorado pikeminnow for radiotag implantation from other riverine sites and off-channel ponds connected to the river in the 15- and 18-mile reaches of the Upper Colorado River. The larger trap nets were a series of two, 1.2 X 1.8 m rectangular hoops followed by five circular hoops that were each 1.2 m in diameter. A center lead, 1.2-m wide X 23-m long, was attached to a vertical center brace of the first rectangular hoop. Square mesh netting (2.54 cm) covered all hoops and the center lead. The smaller trap nets were a series of two 0.9 m X 1.2 m, rectangular hoops followed by five circular hoops that were each 0.9 m in diameter. The center lead was approximately 0.9-m wide X 15-m long. Delta netting with 1.0-cm mesh covered all the hoops and the center lead. Two tapered throats were attached to the first and third circular hoops of both the small and large trap nets. Multi-filament trammel nets (2.5- and 3.8-cm bar mesh) had walls 25 or 30 cm high and were up to 46-m long. Discharge Data Streamflow records for the Gunnison River were obtained from the USGS stream gaging station at Whitewater, Colorado (No. 9152500), to compare mean daily flows among the five years of passageway operation and to examine relationships between river discharge and catches of native fishes in the fish 17