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1). The Delta gauge was above the confluence with the Uncompahgre River and was therefore used in conjunction with the staff gauges at Confluence Park. All other study sites were downstream from the mouth of the Uncompahgre River and therefore the Grand Junction gauge was used for those sites. Although the- gauge was about 40 mi downstream from the most upstream study sites, no other gauges were located within the study reach and it was the most representative gauge. No tributaries with measured flow enter the Gunnison River between the upper study site and the Grand Junction gauge. Several unmeasured tributaries enter the Gunnison between Escalante SWA and the gauge, but they are largely ephemeral and compose a very small fraction of the total flow of the Gunnison River.. Although habitat mapping required 2 days, habitat area was related. to mean-daily flow on the day video was taken. Differences in flow between the 2 days are a potential source of error, but comparison of flows between days for each mapping run indicated that these differences were small (mean, 5.7%; range, 1.1 - 8.3% ). We could not correct for these differences. Results Surface area of habitat at the five study sites was mapped at seven flows; two in each year during 1993 -1995 and one in 1996 (Figure 2; Table 2) .The highest flow when habitats were mapped was 15,800 cfs in 1993 and the lowest was 981 cfs in August 1994, which was the about the lowest flow that occurred in the Gunnison River during the 4 years of study. A-full schedule for the Bureau's helicopter that required reservations more than a week in advance and rapidly changing flows during spring runoff in 1995 resulted in habitat mapping on 2 days with similar flows -13,200 and 13,400 cfs. Total habitat area for the two flows differed by an average of 2.4% (range, 1.4 - 3.7%) at the five sites, so habitat area was averaged for graphical presentation. Because the study sites are river reaches with different habitat components, habitat data were not combined for all sites as has been done in other studies describing shorter sections of river (e.g., Carter et al. 1985; Osmundson et al. 1995). Rather, descriptions of habitat changes are presented for each of the five study sites. The different responses to changes in discharge at the study sites could be used to predict habitat changes in other reaches of the Gunnison River with similar geomorphic configurations. Site 7 This was the simplest study site examined (Figures 3, 4). It consisted of a long run with high banks that contained all flow at the highest discharges examined. The most abundant habitat at 981 cfs was slow run, with small amounts of pools, riffles, 7