Track dinosaurs at natural area

From The Coloradoan, Xplore Section: Track dinosaurs at natural area

Leave only footprints. Take only pictures."

This mantra adorns signs and brochures at parks throughout the U.S. This statement encourages people to leave little trace when enjoying the outdoors.

At Dinosaur Ridge near Morrison, this phrase takes on an entirely different meaning because here visitors can take pictures of the footprints left by dinosaurs more than 100 million years ago for a unique step back in time.

Dinosaur bones were discovered at Dinosaur Ridge in 1877 by Arthur Lakes, a teacher at the new Colorado School of Mines. This discovery led to the identification of stegosaurus, Apatosaurus, allosaurus and the crocodile goniopholis.

Today, the area is considered one of the best preserved representations of dinosaur fossils, bones and tracks. This significance was recognized when it was designated as the Morrison Fossil Area National Natural Landmark by the National Park Service in 1973. It also was designated a State Natural Area by Colorado in 2002 for its scientific, historical and educational significance.

Dinosaur Ridge, which is part of the Dakota Hogback, includes three different formations: the Morrison Formation of the Jurassic period on the west side and the Dakota Formation of the Cretaceous period and the Benton Formation on the east side.

The Morrison Formation is where visitors will see fossilized dinosaur bones. These 150-million-year-old bones came from the bodies of apatosaurus, stegosaurus, allosaurus and diplodocus. The apatosaurus bones were the first bones of a mega-sized dinosaur ever discovered. Commonly called the brontosaurus, this animal weighed up to 33 tons. Cross-sections of the foot imprints of these massive animals can be seen in the rocks.

In 1937, construction started on Alameda Parkway to provide access to Red Rocks Park. This construction exposed hundreds of dinosaur tracks in the Dakota Sandstone. These tracks were later identified as part of the "Dinosaur Freeway," an expanse of megatrack sites that extends from Boulder to eastern New Mexico. Most of these tracks are believed to be made by iguanodons, which lived 120 to 130 million years ago. This plant-eater had a unique thumb spike, which can be seen in the tracks.

The Benton Formation was at one time the bottom of the Western Interior Seaway, an inland sea that covered all of Colorado. In the gray shale, visitors may see 92-million-year-old fossilized fish scales and shark teeth.

There is a 2-mile trail along Dinosaur Ridge, which includes many interpretive signs detailing the history of this unique area.