An evaluation of the streamflow data available in North Dakota was made to provide guidelines for planning future programs. The basic steps in the evaluation procedure were (1) definition of the long-term goals of the streamflow data program in quantitative form, (2) examination and analysis of all available data to determine which goals have already been met, and (3) consideration of alternate programs and techniques to meet the remaining objectives. None of the goals could be met by generalization of the data for gaged basins by regression analysis. This fact indicates that significant changes should be made in the present data program to obtain better areal coverage to achieve the goals set. A streamflow data program based on the guidelines developed in this study is proposed for the future.