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types of sampling gear and techniques were tried during the first sampling trip. Trammel nets were floated through pools; frame nets were set overnight in backwater areas; experimental gill nets were set for short time periods in pools; seine hauls were made with various types of seines; electrofishing was conducted; and a combination of electrofishing and seining was attempted. It was found that a small, bag seine, 15 ft x 4 ft (4.5 m x 1.2 m) with 15 mm stretched mesh yielded best results in slow moving back water areas. Because of the high turbidity of the river, shocked fish could not be easily observed. It was determined that a combination of seining and electrofishing with either a generator (Olsen 240 v) located on the bank, or a backpack shocker (Coffelt 12 v DC battery pack) yielded best results. Sampling protocol with this gear combination was as follows: the seine was stretched from the bank toward the center of the river and electrofishing begun approximately 30 ft (10 m) upstream from the seine and progressed downstream. Narcotized fish and those attempting to avoid the electrical field were captured as the current carried them into the seine. The seine was then brought to shore. This procedure was repeated along approximately 1000 ft (300 m) of shoreline. At each station 300 m of shoreline were sampled in this way. If larval rearing areas were present at the sampling station, one or more of the backwater areas were also sampled. All captured fish were identified and counted. Lengths of endemic fish were determined and all fish, except those that could not be identified because of their small size, were returned to the river. Unidentified specimens were preserved and returned to the laboratory for identification. Rare fish were weighed, measured, and tagged with an anchor tag in the epaxial muscle mass just ventral to the center of the dorsal fin, and released at the point of rapture. Study Area: General Habitat Features Fifteen sample sites were chosen between the Utah-Colorado border and the Uintah and Ouray Indian Reservation eastern border (Figure l). The upper portion of the river had the greatest diversity of habitat. It varied from a s°ngle wide river channel to a braided channel and backwater areas. This resulted in having a variety of riffles, runs and pools available for sampling. Bottom substrate was composed of silt, sand, gravel and/or rubble. Water velocities varied from very slow in the backwater pools to swift in some portions of the main channel. Proceeding downstream, habitat became less diverse as the river widened and contained fewer large backwater areas and side channels. At downstream sites, the bottom substrate was mostly silt,