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1998-Tagged Fish Capture and Release. Four adult Colorado pikeminnow captured in the Lower Gunnison River between the Redlands Dam plunge pool and the confluence with the Gunnison River were implanted with 29-gram LOTEK° transmitters between 18 May and 22 June (mean TL=691 mm; range=594-767). These fish were then translocated and stocked upstream of the Redlands Dam in the Gunnison River. Three fish were released at Whitewater (RM 14.7) and one at Bridgeport (RM 29.3). Two other adult pikeminnow captured in the 15-mile reach of the Upper Colorado River were also implanted with 29-gram LOTEK° radio transmitters during-April. These two fish were part of another ongoing study to evaluate the potential use by endangered and non-endangered native fishes of the recently constructed fish passageway and notch at the Grand Valley Irrigation Company's diversion dam at Palisade, Colorado (Appendix; Table J.1.). The movements of these two fish were included in this study because there was every likelihood that they could move downstream from their release point in the Upper Colorado River, move upstream in the Lower Gunnison River, and migrate through the passageway at Redlands. Movement and Dispersal. In 1998, three of the four fish translocated and released at two different sites upstream of the Redlands Dam moved downstream over the dam in late-June just prior to the spawning season. Three of these four fish continued traveling downstream in the Gunnison River and entered the Colorado River. One pikeminnow was detected in mid- and late-July in Horsethief Canyon at RM 145 in the Colorado River. One other pikeminnow was found in mid- July at RM 164, immediately upstream of WWWA. It is speculated that these fish were moving downstream in response to descending flows and were returning to the Colorado River to spawn (Appendix; Table K.7.). The location of one pikeminnow (Code 117) was unknown from late-June until early-November. Two of the three radio-tagged pikeminnow returned in early-August to the Lower Gunnison River. These two fish were ultimately located in the plunge pool of the Redlands Dam on 8 August. They both remained there for 20 days. Contact was reestablished with all four of the pikeminnow implanted with radiotags in 1998 until late-September. Contact was made in early-November with two of the translocated pikeminnow.. One fish (Code 117) was contacted at RM 157 and the other (Code 116) at RM 146 in the Colorado River. The fourth pikeminnow (Code 121) remained upstream of the Redlands Dam in the Gunnison River and was last located at RM 3.4 on 8 August (Appendix; Table K.3.). Monitoring of four pikeminnow radiotagged in 1998 was scaled back following spawning because three of the four fish had moved downstream over Redlands Dam, the fate of the four fish following release upstream of the dam was known, and the radiotags would expire before the 1999 spawning season. Therefore, the duration of time that these pikeminnow were monitored and contacted by boat was 42