A passing storm reveals a thick mantle of snow draped on the folds of the Third Flatiron. An icon of Colorado’s Front Range, the Third Flatiron rises over 1400 feet in a single thrust of rock. The Flatirons and foothills are an uplift of Precambrian and sedimentary rocks that mark the spectacular boundary between the plains and Rocky Mountains. Part of Boulder Open Space and Mountain Parks, the area is home to several threatened species, including the Peregrine Falcon.