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estimates for 2002 and 2003 that were only slightly lower than those for 2000 and 2001, in spite of small capture samples. However, with the exception of 2001, the limited number of fish captured and recaptured in the Yampa River resulted in abundance estimates that were relatively imprecise (high CV's, wide CI's) so definitive statements about the status of Colorado pikeminnow in the Yampa River were difficult to make. Declines of adult Colorado pikeminnow in the White River and middle Green River reach appear more pronounced and were particularly important because those areas represented the largest segments of the Green River Basin population. Abundance reductions in the middle Green River reach may even be conservative given that the 0-analysis suggested that area was a sink for Colorado pikeminnow moving from other reaches. The slope estimate for regression relationships of loge abundance as a function of time is an estimate of the percent annual change in the population. The negative and relatively large slope estimates for the White River and the middle Green River reach suggested that the factor(s) influencing apparent basinwide abundance declines were more acute there. Decline in abundance of adult Colorado pikeminnow in the lower Green River reach was not as severe as in the middle Green River reach or the White River. A relatively small apparent decline in the Desolation-Gray Canyon reach occurred over the term of the study. The smaller reduction relative to the other reaches may be due to the relatively large number of Colorado pikeminnow moving into that reach annually, as shown by the transition rate estimates. Trends in point estimates also suggested a decline in abundance of recruits for most reaches where they occurred, with the exception of the lower Green River, where they apparently increased slightly in 2003. Abundance estimates for recruits in each river reach generally had relatively broad and overlapping confidence limits. 44