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field data, was compared against six other simulations which assumed that Colorado squawfish represented 1 %, 2 %, 3 %, 5 %, 10 %, or 25 % of the diet by weight for all age classes throughout the year. Spatial-temporal overlap of northern pike with juvenile (age-0 to age-3) Colorado squawfish indicated that the opportunity for predation remained throughout spring and summer in backwater habitats, and that overlap was probable during winter when all species were concentrated in scarce deep pools used as overwinter habitat. Seasonal consumption by individual pike from each age class was expanded to seasonal, population-level predation rates by multiplying age-specific individual consumption times the proportional age structure of pike found in field collections. We assumed the size and age structure from our field collections were representative of the population since pike were captured with trammel nets, by electrofishing, or by using electroshockers to herd pike into trammel nets. Since accurate estimates of northern pike abundance in the Ouray reach were not known, population-level predation rates were computed for 1,000 pike conforming to -the observed size and age distribution. Results Seasonal Movements and Thermal Experience of Pike To adjust daily metabolism for increased energy loss due to activity, 29 pike implanted with radio transmitters were monitored to estimate movement dynamics. Large-scale movement ranged from 0.2 to 2.6 miles per day for the 29 radio-tagged pike. The mean movement per day was 0.56 miles (0.67 S.D.). Over the course of the study, the maximum movement was 120 miles. Overall, there was a net. upstream movement of 4.9 miles over the year-long study.