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The Yampa River within Dinosaur National Monument was divided into four strata based on a longitudinal gradient (Table 1, Figure 1). The longitudinal stratification of the reaches was an effort to remove any variation associated with fish abundance that may occur in a downstream gradient in the Canyon that affects bedrock type and changes in habitat occurring in the Yampa River as channel substrate size declined downstream. Each stratum (between 13 and 18 kIn long) was equally divided into two reaches, and the subdivided reaches were randomly designated as either a treatment or control reach. Channel catfish were removed from treatment reaches during each pass through the canyon. Catfish were only removed from the control reaches during the final pass of the field season for comparison of relative densities from removal (treatment) and non- removal (control) reaches. In 1998, fish from both control and treatment reaches were collected and removed during a single trip. In 1999, greater effort was applied to each reach and two trips were required to complete the final pass (two treatment and two control reaches sampled per trip). Specific treatment and control reaches sampled during the last pass in 1999 were randomly assigned. Strata boundaries remained constant through both years of the study. During 1998 several gear types were used to determine the most efficient means of removal. These methods included electrofishing, fyke nets, hoop nets, and trot lines, and angling. Removal Methods The initial effort in this study was directed toward identifying gear efficiency in removing channel catfish. In 1998, electro fishing, angling, netting (fyke and hoop nets), and trot lines were used to capture and remove channel catfish (see table 1). Effectiveness was measured by both the number of fish captured per hour and cost per fish removed from the canyon. Lengths (of all 4