Peak-flow frequency analyses for selected streamgages on tributaries of the Bighorn, Tongue, and Lower Yellowstone Rivers, based on data through water year 2021

The USGS Wyoming-Montana Water Science Center (WY–MT WSC) completed a report (Sando and McCarthy, 2018) documenting methods for peak-flow frequency analysis following implementation of the Bulletin 17C guidelines. 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. This data release presents peak-flow frequency analyses for selected streamgages on tributaries of the Bighorn, Tongue, and Lower Yellowstone Rivers, based on data through water year 2021 that were based on methods described by Sando and McCarthy (2018).