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26 for a number of reasons. First, access was easier and more backwater areas exist in this section, which permitted procurement of large numbers of small fish to identify by length-frequency analysis young age-groups for the various species. Vincent (1966) noted considerable difficulty in capturing small, young fish in the National. Monument sections. Further- more, almost all the species that are found in the Gunnison River were collected below the North Fork, and this allowed us to establish early reference collections for the various species and hybrids. Intensity of fish sampling shifted to the areas above the North Fork in 1976 and 1977. Although a few hauls with a 25-ft bag seine were made in 1976 in this area, most fishes were collected by gillnets and some by hook and line. Gillnets were stressed so the data would be more comparable to those collected by Kinnear and Vincent (1967) in 1965-66 before the Curecanti Unit was in full operation. Most (75X) of the fish collected by them were taken in 1965 before the closure of Blue Mesa Dam. Vincent (1966), reporting on 713 fish from the 1965 collections in the Monument, mentioned that seining had been fruitless while fishing with set-line and rod and reel were of limited value. He continued that electrof ishing was limited by adverse water conditions and variable-mesh gillnets had proved to be the most efficient type of sampling gear. During the present study seining was done most frequently in back- water areas where flow was not excessive. For the main river samples, gillnets were usually set overnight parallel with the flow or at a slight angle across the flow. Sets made directly across the stream flow were unproductive because they became clogged with debris and algae carried in the main flow. Nets were normally anchored to the bottom and tied to a tree or rock along the bank, but on occasions