Following the success of the Center for Western Studies' first foray into river histories, Heartland River: A Cultural and Environmental History of the Big Sioux River (second printing, 2025), the CWS is publishing The Missouri, America's Longest River in 2026 as part of its commemoration of America's 250th anniversary. The book features chapters by thirty-five historians, scientists, and writers exploring the natural and human history of the waterway that defines the region that is the focus of the Center for Western Studies—South Dakota and the six surrounding states.

Chapter contributors represent the following institutions: Augustana University, College of New Jersey, Helena College, Loras College, Loyola University, Midland University, Minnesota State University–Mankato, Nebraska Game and Parks Commission, Northern Illinois University, Ohio State University, Oklahoma City University, Providence College, South Dakota School of Mines, South Dakota State Historical Society, South Dakota State University, State Historical Society of North Dakota, University of California–Riverside, University of Colorado–Boulder, University of Kansas, University of Kansas–Monticello, University of Nebraska–Lincoln, University of South Dakota, and the United States Geological Survey.