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strata. Correlation analysis suggested that depth, wetted width, and velocity explained the greatest variability in stream morphology among all strata. A linear regression was used to estimate the point at which decreases in flow caused the greatest habitat change in each channel within eachmesohabitat (i.e., run, riffle, or pool). The point of the regression curve where the greatest rate of decrease in stream channel variables occurred with flow was identified as the curve break. Each habitat variable (wetted width, depth, velocity, etc.) was plotted against low flow scenarios (1 to 300 cfs) identifying where the largest residual occurred in the graph (i.e., the greatest difference between regression line values and the corresponding actual data points). The curve break, indicated the specific flow (cfs) that a given habitat variable (e.g. width, depth, etc.) declined at the greatest rate per mesohabitat type. Analysis of variance indicated that no differences in the curve break flows for riffles was detected among strata, therefore, the entire study area could be considered a single reach for purposes of the flow recommendation. Because riffles are the most sensitive mesohabitat type to changes in flow, their importance to foraging behavior of pikeminnow, and their role in invertebrate production, they were emphasized relative to development of flow recommendations. Flows identified by curve breaks were within a fairly narrow range both within and among mesohabitat types. The mean curve break flow for riffles, 93 cfs, was somewhat higher than the flow for runs and pools. The curve break flow for suspected nocturnal foraging pikeminnow was 88 cfs, which suggests that the 93 cfs will also maintain adequate foraging habitat for endangered Colorado pikeminnow in the upper strata. Curve breaks generated from estimates of weighted useable area were similar to, but, somewhat higher than the mean generated from channel variables. Habitat Use Radio telemetry observations showed that Colorado pikeminnow in the Yampa River above Yampa Canyon exhibited different behaviors during day and night. After sunset, pikeminnow moved actively within a discrete habitat (e.g. pool, run or riffle) suspected to be foraging-related movements within or to another discrete habitat. In 1996, a low baseflow year, radio-tagged fish remained within the habitat unit (pool or run) where they were observed during the daylight hours. After sunset, fish either actively moved over the entire habitat or moved to the upstream or downstream interface with the adjoining habitat. In 1997, an extremely high baseflow year, fish showed similar diel activity behavior as in 1996. Fish were most active after sunset and exhibited what appeared to be a foraging behavior. Some of the fish remained within a discrete habitat while other fish were observed to move to another habitat during this apparent foraging behavior. Two of the fish observed in 1997 did move through several discrete 10