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In an effort to develop a localized/regional regression equation, 11 stream gages, with at least 10 years of record, were located and analyzed to predict the peak flows for the selected recurrence intervals. The gage numbers and station names are listed below: Station No. 09239500 09244410 09247600 09241000 09242500 09238500 09238900 09238750 09238710 09237500 09237450 Station Name Yampa River at Steamboat Springs Yampa River Below Diversion, Near Hayden Yampa River Below Craig Elk River at Clark Elk River Near Milner Walton Creek Near Steamboat Springs Fish Creek at Upper Station Near Steamboat Springs Middle Fork of Fish Creek Near Buffalo Pass Fish Creek Tributary Below Long Lake, Near Buffalo Pass Yampa River Below Stagecoach Reservoir Yampa River Above Stagecoach Reservoir Two of the stream gages, Yampa River Below Stagecoach Reservoir (09237500) and Yampa River Above Stagecoach Reservoir (09237450), were removed from the analysis for reasons summarized below. First, significant storage exists upstream of the Stagecoach Reservoir gages. Three reservoirs upstream of Stagecoach Reservoir (Stillwater, Yampa, and Yamcolo Reservoirs) hold a combined capacity of roughly 16,000 acre-feet. In addition, runoff is divert~d at two locations on the Yampa River upstream of Stagecoach Reservoir. The second reason is that according to USGS personnel, the soils in the tributary drainage basins have very high infiltration rates and as a result lower the peak flows. The effects of upstream detention were evaluated for the Yampa River at the Steamboat Springs gage. Five reservoirs or lakes upstream of the gage were identified and store a combined volume of approximate 57,000 acre-feet, but none of these serve exclusively for flood control. Through contact with the Upper Yampa River Conservancy District (UYRCD), it was learned that when the reservoirs fill, during the months of May and June, peak flows are also recorded at the gage in Steamboat Springs. As a result, an investigation was made into the effects of the upstream storage on the peak flows recorded at the Steamboat Springs gage. Both the USGS and the UYRCD were contacted to determine if any stage readings on the reservoirs exist, in order to develop a relationship to the peak flows at the Steamboat Springs gage. Because no reliable or continuous stage recordings exist for the reservoirs, other methods were sought to eliminate the error associated with the upstream reservoirs. To eliminate the effects of upstream storage, a log-Pearson Type III analysis was performed on the peak flows in the dataset up to the time when the first reservoir, Stillwater, was built in the late 19308. The predicted peak flow from this dataset, which consisted of roughly 29 years of record, was in agreement with the loo-year predicted peak flow from recent publications (Reference 13) and agreed more closely with the predicted flows from the trendline analysis. 24