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-31- Maximum daily high air temperatures reached 100-1010 F on July 5-6, 1991. While there were 19 days when the maximum daily high air temperature exceeded 900 F during July 1991, there were no such days during June and only one in August. It seems safe to conclude that the summer of 1991 was as unusually cool along the Dolores River corridor as the summer of 1990 was unusually hot. The combined effects of the cooler air temperatures and the 60-70 cfs flow regime resulted in a decrease in the probability of further serious damage to the stream fishery that might have occurred in the event of long periods of maximum daily high air temperatures of 100-1100 F. Water Temperature versus Stream Discharge - Air temperature data for the Bradfield Bridge Station was not col1ected during 1990 to compare with 1991. However, comparison of daily water temperature data for 1990 and 1991 (at river miles [RM] 6.6 and 12.2) lead one to conclude the Dolores River corridor experienced a much cooler summer in 1991 compared to 1990. The data in Table 16 is a comparison of water temperature data at RM 6.6 and 12.2 for 1990 and 1991. Brown trout growth ceases when mean water temperatures reach 19 C (Celsius) or 66.20 F according to Elliott (1975a,b). McMichael and Kaya (1991) reported angling success for rainbow and brown trout drops significantly when the water temperature exceeds 19 C (66.20 F). There were eight times the number of days in 1990 (compared to 1991) when the maximum daily water temperature (at RM 12.2) exceeded 700 F. Similarly, there was more than a month (of days) when the mean daily water temperatures exceeded 660 F in 1990, but none in 1991. Comparison of air and water temperature data (together with stream discharge records) for 1991 reveals that with flows in the 30-35 cfs range, mean daily air temperature and average daily water temperature was approximately equal at RM 6.6 in the early spring (April-May) and late-summer (September). At 35 cfs, average daily water temperature at RM 12.2 exceeded mean daily air temperature by 5 F. Similarly, at a discharge of 50 cfs, mean daily air temperature and mean daily water temperatures were approximately equal at the Bradfield Bridge (RM 12.2). At 60 cfs, mean daily water temperature at Bradfield Bridge was about 2.5 degrees F cooler than the mean daily air temperature. Mean daily water temperature at Bradfield Bridge was 5_60 F cooler than mean daily air temperatures when the flow was 71 cfs. Finally, when maximum daily air temperatures reached 95-1000 F, maximum daily water temperatures at the Bradfield Bridge reached or exceeded 700 F when the river was running 70 cfs.