In the early stages of Pick–Sloan development, tentative plans were made to build a low dam on the Missouri at Riverdale, North Dakota and 27 smaller dams on the Yellowstone River and its tributaries.
Nas primeiras etapas do desenvolvemento Pick-Sloan fixéronse plans tentativos para construír unha presa baixa no Missouri en Riverdale (Dacota do Norte) e 27 presas máis pequenas no río Yellowstone e os seus afluentes.