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The five homogeneous strata were as follows: Length Stratum.Mi (km). River milesa km Land Mark Description V 17.5 (28.2) 132.5-150 213.2-241.4 1 mi (1.6 km) above Yellow Creek to Rio Blanco Lake. W 38.3 (62.0) 94.2-132.5 151.2-213.2 Hwy 64 bridge in Rangely to 1 mi. (1.6 km) above Yellow Creek-White River confluence. X 34.9 (55.8) 59.3-94.2 95.4-151.2 Ignacio Bridge to Hwy 64 bridge in Rangely. Y 38.0 (61.1) 21.3-59.3 34.3-95.4 Mt. Fuel Bridge to Ignacio Bridge State Route 45, 111 mi south of Bonanza. Z 21.3 (34.3) 0.0-21.3 0.0-34.3 Confluence to Mt. Fuel Bridge a River miles from confluence of White and Green rivers. Sampling Design and Procedure Sampling procedures followed those presented in Archer et al. (1980). A random sampling design was utilized to establish the sampling sequence. One stratum (Y) was selected as the starting point, the samp- ling series progressed sequentially downstream to the last stratum (Z) then shifting back to the uppermost stratum (V) to complete the series. Within each stratum, sample stations were selected according to a random sampling design. In order to avoid sampling bias in the selection of stations, a table of random digits was consulted and the first number encountered in the table that corresponded to a river mile in the section was chosen for the first sample station. To permit replication and to ensure that representative stations were chosen, each station consisted of two 0.5 mi reaches; one extending downstream from the selected river mile starting point, the other five mi downstream (Figure 3). Intensive sampling began in the uppermost 0.5 mi (0.8 km) section continuing for 24 h. The second day, the intervening 4.5 mi section was surveyed by electrofishing starting at the lower boundary of the previous sample station and continuing downstream to the upstream point of the second 0.5 mi station. From this point, the second 0.5 mi section was intensively sampled for 24 h. Within each 0.5 mi (0.8 km) station, discrete habitat types were delineated and fish collections were conducted within them, rather than across several habitats. This permitted a delineation of habitat prefer- ences for fish species with depths, velocities and substrates recorded for each subsample. 5.