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CONCLUSIONS 1) Growth rate in Colorado squawfish older than 10 years is slower than previously thought. 2) Annual increases in length average 82 mm per year in 3-year-olds but decline to 4 mm per year in fish > 800 mm long. 3) Size at which most individuals reach sexual maturity (428-503 mm TL; Seethaler 1978) is attained at about seven years of age. 4) Size of fish of a given age is highly variable: simulations indicated lengths of 10-year- olds may vary by 100 mm; of 20-year-olds, 200 mm. 5) Longevity is likely greater than previously thought; simulations indicated that most individuals 800 mm long are estimated to be between 20 and 40 years old; those 900 mm long are estimated to be at least 32 years old and perhaps considerably older. 6) Annual adult survival rate is not particularly low; two separate estimators produced consistent results: 0.86. 7) Historic growth and survival rates are unknown. 8) Average size of Colorado squawfish in the Colorado River increases in an upstream direction; over time adults become concentrated in the upper reach. 9) Though subadults and adults are found in backwaters throughout the river during spring runoff, some backwaters have consistently higher catch rates than others. 10) Small adults move greater distances over time than do larger adults, and fish in the lower reach (mostly small adults) move greater distances between captures than do fish in the upper reach. 11) There is considerable movement of adults from the lower to the upper reach but little to no movement from the upper to lower reach. 12) Body condition of subadults is high during spring in the lower reach but declines as they grow to adult size; conversely, in the upper reach, condition increases as adults grow. 13) Net displacement of adults to the upper reach and improved body condition is likely related to significantly higher densities of native forage fish there. vi