| This view is looking south toward the Sierra De San Vicente in northern Mexico from the unpaved River Road in southern Big Bend National Park. The mountain range is a large fold (a plunging anticline) in Cretaceous limestone that is being exhumed by the gradual regional erosion in the Big Bend/Rio Grande region. The river flows in a canyon on the north side of this great fold (hidden in the low gray hills around the fold). Creosote bush (Larrea tridentata) and a few scattered spring wildflowers are all that grow amongst the rocky desert pavement (USDA, [2010]). A section of the River Road is to the left. |
