The new equations, which are applicable to streams that are not substantially affected byregulation, impoundment, or surface-water withdrawals, are from the following report, which users should review and understand before attempting to obtain peak-flow statistics for this area:

• Smith, S.J., Lewis, J.M., and Graves, G.M., 2015, Methods for estimating the magnitude and frequency of peak streamflows at ungaged sites in and near the Oklahoma Panhandle: U.S. Geological Survey Scientific Investigations Report 2015–5134, 35 p.