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METHODS FISH SAMPLES Fish were electro-shocked and netted from an Achilles raft using a Smith-Root electro- fisher powered by a SOOO-watt generator with the anode mounted on a forward boom. The boat was maneuvered by either oars or by a battery powered 40 pound trolling motor. Two netters caught as many fish as they could while the shocker was in operation. All fish were measured to the nearest millimeter. Only fish over 150mm were marked and therefore used for mark and recapture population estimates. The Darroch multiple mark method (Everhart and Youngs 1981) was used to estimate abundance with ninety-five percent confidence intervals. Sections of river both up and downstream of the mapped site were electrofished on the Yampa and Colorado Rivers. Fish were measured and released at specific locations in each study reach. The stops were typically above each riffle. This allowed for a qualitative assessment for species composition and relative abundance in each riffle-run sequence in the sample reach. On the Yampa River a different mark was used for each run-rime sequence, which allowed for determining if recaptured fish had moved up, down or had not changed sequences between captures. Four total passes were made at the Sevens stations, on August 30, September I, 14 and 16. Flow on those dates (Maybell gage) were 315 cfs, 280 cfs, 219 cfs and 201 cfs, respectively. The reach from the Duffy run above the launch to the lower end was electro-fished on August 25, September 2, 15 and 17. The flows on those dates were 302 cfs, 347 cfs, 293 cfs and 265. The upper section and the run directly upstream of the launch site were electro-fished on August 23,24, September I, and September 7 at flows of340 cfs, 302 cfs, 3 18 cfs and 370 cfs. 12 I I I I I I I I I I I t I I 1 I I I I