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Colorado pikeminnow collected in the fish trap were weighed (g), measured (TL-mm), and checked for a PIT tag. If they had not been previously marked, they were PIT-tagged. All Colorado pikeminnow that were collected in the fish trap, including the four Colorado pikeminnow that were implanted with radiotags in 1999, were released immediately upstream of the diversion dam. In 1996, all non- endangered native fish collected in fish trap between 24 June and 6 September were marked (left pelvic fin-clip) and released upstream of the dam to determine dispersement and distribution following release. Dispersement and distribution of marked fish that moved upstream from the dam were determined by systematically electrofishing with two boats downstream from Hartland Diversion to Redlands Diversion Dam in late-September 1996. Recaptures of marked fish in the fish trap indicated that they had fallen back over the dam and reascended the passageway. In addition to collecting fish data from the fish trap, crews were responsible for removing riverborne sediment from the fish trap that usually built up during runoff, and routine (daily) cleaning of surface and submerged trash, debris, and algae from the trash grates and bar screens in the forebay of the passageway, and aluminum conduit screens in the fish trap. The amount of algae, debris, trash, and sediment that accumulated daily at this site was seasonally variable, depending upon flow magnitude and water volume during the water year. FWS crews were also responsible for opening and winterizing the fish passageway. Radiotelemetry The spatial and temporal movements of radio-tagged sub-adult and adult Colorado pikeminnow were monitored by tracking fish from boats and from fixed, semi-permanent, land-based tracking stations. Radiotelemetry provided data on the movement and fate of sub-adult and adult Colorado pikeminnow in the immediate vicinity of the Redlands passageway, in river reaches up- and downstream of the passageway in the Gunnison River, and reaches of the Colorado River up- and downstream of the confluence with the Gunnison River. This was the first passageway constructed specifically to pass Colorado pikeminnow and razorback sucker. Telemetry was used because it was uncertain whether Colorado pikeminnow or razorback sucker would use the passageway. If Colorado pikeminnow or razorback sucker were collected in the forebay fish trap, this would obviously indicate that they had negotiated the passageway. However, if fish were not found in the fish trap, there were several possible explanations: 1. The fish could not reach the passageway because downstream flows in 13