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that the results are reasonable. The fact that 21 additional years of peak flow data are now available also increases confidence in the results of the current study. For the Roaring Fork and Fryingpan Rivers, the hydrologic analyses were completed by the USACE (Reference 17). A regional analysis of stream data taken at gages in the Roaring Fork Basin was performed and natural flow frequency curves were developed. The peak flows determined for the 10-, 50-, 100-, and 500-year floods were used to determine the flood profiles and the 100-year floodplain for this report. Data from a large number of stream gaging stations located within the homogenous watershed area similar to this area were analyzed. These gages are located within Pitkin County and nearby Summit, Eagle, Garfield, Mesa, Delta, and Gunnson Counties. The streamflow data were separated into snowmelt and rainfall peaks and analyzed separately. Snowmelt peaks from a total of 40 gages and rainfall peaks from 25 gages were analyzed to obtain individual and regional statistical parameters of mean, standard deviation, and skew for the two types of flow peaks. In numerous instances, the rainfall peaks were of very small magnitude. Several stream gages did not show any significant peaks caused by rainfall. Using log-Pearson Type III distribution as described in U.S. Water Resources Council Bulletin 17 A, the discharge-frequency information was developed separately for the snowmelt peaks and the rainfall peaks for the 10-, 50-, 100-, and 500-year recurrence intervals. These two distributions were combined to obtain the overall peak discharge-frequency relationship for each stream. For ungaged streams, the values of regional statistical parameters were used and the drainage area curves were developed for the 10-, 50-, 100-, 500-year recurrence intervals. Peak discharges for the Roaring Fork and Fryingpan Rivers are shown in Table 1. 21