We stopped at Horseshoe Canyon. It is a pocket of badlands located 17 kilometers from Drumheller. In this mini-Grand Canyon of brownish-grey mudstone, white sandstone, black coal and reddish siltstone, a river once flowed to the shallow sea that covered most of the Alberta during the Cretaceous. Over time, the mudstone and sandstone have eroded into strange-looking mushroom-like caps supported by columns of sediment. These are called hoodoos. The skeletons of over 50 dinosaurs have been discovered in this area of the badlands.