Description:Harvey details the first major clash between conservationists and developers after World War II, the successful fight to prevent the building of Echo Park Dam. The dam on the Green River was intended to create a recreational lake in northwest Colorado and generate hydroelectric power, but would have flooded picturesque Echo Park Valley and threatened Dinosaur National Monument, straddling the Utah-Colorado border near Wyoming. Mark W. T. Harvey is associate professor of history at North Dakota State University in Fargo.