Yampa River Canyon / Dinosaur National Monument
Yampa River Canyon just downstream from Warm Springs Rapids. The rapids were created by a large landslide in 1965 that blocked part of the river and redirected its flow into a narrow gap. The canyon wall at river level on the right is cut into the Morgan Formation, a middle Pennsylvanian sequence of limestones, sandstones and siltstones. The canyon wall in the distance is the overlying Weber Sandstone, a thick mass of dune sands that is late Pennsylvanian and early Permian in age. Dinosaur National Monument. Moffatt Co., Colo.