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Methods -Fish Community Fish community monitoring was conducted at three locations established for the Interagency Standardized Monitoring Program (ISMP). Those sites were: Muier's Cabin (RM 124.3-124.1), Cougar Bar (121.5 - 121.1), and Hades Bar (RM 120.1- 119.9). Each site is bounded upstream and downstream by a rifle area. Depth measurements collected in May 1994 revealed the following ma~dmum site depths :Miner's Cabin - 21.8m, Cougar Bar - 19.5 m and Hades Bar - 10.6m. Fish community sampling was conducted at the three trend sites within Westwater Canyon. On these trips fish were sampled in main channel habitats with trammel nets (23m x 2m; 2.5 and 1.25 cm mesh), shorelines were sampled with sport boat mounted pulsed DC electrofishing and lm hoop nets. Sampling was conducted primarily during the crepusculaz and night. time hours. Trammel nets were checked every two hours, hoop nets were fished through the night. After capture, Gila spp. were transferred to holding pens, held through the sampling night, processed the following morning, and then released. Standardized catch rates are presented as fish /23m net hour for trammel net catch, and fish /hour electrofishing. The following information was collected from all chubs captured: total and standard length (mm), weight (g), dorsal and anal fin ray counts. In 1991, while conducting the Gila taxonomy trips, the UDWR received training in sexing Gila spp. from Dr. M Douglas; Arizona State University. Chubs larger than 200mm TL were sexed by examining the urogenital opening., Body scales were collected each trip from a representative sub-sample of the catch. Chubs iri excess of 175mm TL were PTT tagged. Recaptured fish provided data for analyses of movement and growth. For the present study movement was described as capture at a location other than the site of previous capture. Distances between sites were 2.6 miles from Miner's Cabin to Cougaz Baz, 1.5 miles from Cougar-Bar to Hades Bar, i.e 4.1 miles overall. Recapture data was also used to estimate population size using sequential (yeaz to subsequent year) Lincoln-Peterson estimates. All statistical analyses were run on the STATIS77X statistical package. Flow and temperature data was gathered by the United States Geological Survey (USGS) at the State Line gage and the Near Cisco, Ut gage. River locations presented as river miles from the Green and Colorado Rivers confluence and flow volumes have been presented in English units. All other units of measure are metric. DRAFT 7.