1955 Map of Split Mountain

About this map

The Green River carves a dramatic path through the heart of Dinosaur National Monument, defining a landscape where geology and early ranching intersect. This mid-century survey illustrates the river's treacherous descent through Split Mountain canyon, identifying a series of formidable whitewater features including Moonshine Rapids, Inglesby Rapids, and the provocatively named SOB Rapids. While the northern half of the sheet is dominated by the steep walls of Mitten Canyon and the Yampa Plateau, the southern reaches show signs of human activity in this remote Utah terrain.