Peak-flow frequency analyses for selected streamgages in Wyoming, based on data through water year 2022

The USGS Wyoming-Montana Water Science Center (WY–MT WSC) completed a report (Siefken and others, 2025) documenting methods for peak-flow frequency analysis following implementation of the Bulletin 17C guidelines. This data release, published in cooperation with the Wyoming Water Development Office, presents peak-flow frequency analyses for selected streamgages in Wyoming, based on data through water year 2022, using the methods described by Siefken and others (2025). The methods are used to provide estimates of peak-flow quantiles for 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEPs) for selected USGS streamgages. The computation of peak-flow frequency statistics in this data release is part of a larger study to develop a StreamStats application (https://www.usgs.gov/streamstats) for the State of Wyoming. The child items in this data release contain analysis specification files, peak flow data files, and results of peak-flow frequency analysis for the selected streamgages. Files for each child item are organized by 2-digit hydrologic unit code (HUC). 

Disclaimer: These specifications files are not compatible with earlier versions of PeakFQ. Note that because the peak-flow data are in the WATSTORE format, the analysis cannot be run if PeakFQ 8.0.1 is hosted on a web server, rather than running on a local computer.