WHEN you stand on the edge of the Red Deer River valley, just south of the town of Drumheller in Alberta, Canada, you stand on the edge of two different worlds. At eye level, in every direction, are the endless wheat fields of the Alberta prairies. But looking down the cliffs into the dry and barren valley, visitors can imagine another world far removed from their own​—the world of the dinosaurs.

In this valley, with its steep canyons of multicolored sedimentary rock layers, hundreds of dinosaur bones have been unearthed. Some people in this area call the barren canyon “the badlands.” But visitors, young and old alike, are filled with astonishment as they view the fossil legacy of some of the most amazing animals that ever lived on earth.

Large quantities of dinosaur remains​—including such nonskeletal evidence as tracks—​have been unearthed in the Great Central Plain of North America. The prairies of central Alberta have yielded many dinosaur remains, including almost 500 skeletons, many of them nearly complete.

In the Red Deer River valley, there is a layer of sedimentary rock that contains dinosaur bones. Just above this, there is a purplish-​brown layer that follows the contour of the hillside. On top of the purplish-​brown layer is a layer of brownish siltstone containing fossils of subtropical ferns, indicating a hot climate. Above this, there are several layers of coal. Farther up the hillside are coarser-​grained layers of earth. There are no dinosaur bones in any of the higher layers.

The book A Vanished World: The Dinosaurs of Western Canada states that “all of the 11 major kinds of dinosaurs . . . ceased to exist in the western interior at about the same time.” This, and the fact that human bones have not been found with dinosaur bones, is why most scientists conclude that the Age of Dinosaurs ended before humans came on the scene.