Streamflow characteristics as of 1984 for the Missouri River Basin, Wyoming, based on data from 204 streamflow-gaging stations are summarized. The streamflow characteristics reported include mean monthly and mean annual streamflow; duration of daily mean flow; and magnitude and probability of instantaneous peak flow, annual low flow, and annual high flow. Recurrence intervals of 2, 5, 10, 20, or 50, and 100 yr are determined for the peak-flow, low-flow, and high-flow characteristics. Annual low-flow and high-flow characteristics are also listed for various numbers of consecutive days. A station description, tables of streamflow characteristics, and graphs of mean monthly streamflow and duration of daily mean streamflow are presented for each station. Streamflow characteristics for periods before and after dam construction or transbasin diversion are presented for six stations. (USGS)