The water management history of the Pick-Sloan Missouri River Basin Program was analyzed with particular emphasis on federal, State, local and non-governmental institutional arrangements and an evaluation of performance of these institutions over a 28-year period, 1944-1972. The statutory bases for these institutions was documented. Performance criteria included effectiveness in regional policy, planning, programming and operational management and their responsiveness to social change. The regional economy was compared in 1940 and 1970, in the light of expectations of the original plan and actual realization of intended results, with emphasis on the role of water. The analysis prompted recommendations for new institutional re-orientations for the future that would better serve the needs of multi-State regionalism.