Dinosaur tracks, fossils draw visitors to Southern Utah

Located at 2180 E. Riverside Drive, the St. George Dinosaur Discovery Site remains open Mondays through Saturdays all year from 10 a.m. to 6 p.m., Mountain time. The site lies 120 miles from Las Vegas. Turn off Interstate 15 when you reach St. George at the Bluff Street exit and turn right, then left to reach Riverside Drive. Follow this drive a couple of miles to a well-marked parking area near the large glass and metal museum structure. Expect to pay a $6 entrance fee per person aged 12 or older and $3 for children aged 4 through 11. Children younger than 4 enter free of charge.

Recognized as the most significant dinosaur track site in North America, the St. George Dinosaur Discovery Site at Johnson Farm is regarded as one of the most important such sites yet discovered in the world. Thought to be located on the margins of an ancient lake, the site continues to enrich our knowledge of the Early Jurassic Epoch between 195 million-198 million years ago. It has yielded tracks of many kinds of dinosaurs, including one upright predator that squatted, leaving haunch and tail imprints and tracks of its clawed forefeet. Work has uncovered imprints of dinosaur skin, fossils of fish, swim tracks left in the shallows, aquatic and terrestrial plants and evidence of other animals of the time.

Dr. Sheldon Johnson never dreamed his small farm on the outskirts of St. George contained a treasure trove of dinosaur tracks, although scattered tracks had been found at several locations in the sandstone of Southern Utah. In February 2000, as Johnson worked to level a rocky outcropping, a large slab of sandstone tipped out of the bucket of the machine he used. It split apart along ancient sedimentation lines to reveal foot-long natural casts of tracks left by a large three-toed creature.

Intrigued, Dr. Johnson examined the layers and determined that his initial discovery was just a sample of what lay hidden. He soon called experts to assess his find. As word spread about the tracks, hundreds of curious visitors showed up at the farm. Eventually, Johnson donated 10 acres of his land to the City of St. George for protection of the tracks and development of a museum. Construction of the 15,000 square-foot museum facility was completed in 2005.

Today, the city employs a paleontologist and staff to operate the site as a museum with educational outreach. Johnson’s original find led to the discovery of thousands of tracks and associated fossils as more of the site was explored. Much of the continuing work is done by volunteers under direction. Visitors often return to the site to spend their time digging and toiling in the sun with the experts and happily pay a fee to do so.

The fossils at the Johnson Farm indicate the ancient shoreline was a lush landscape with plants resembling ferns. Over a long span of time, many kinds of dinosaurs of varying sizes inhabited the area and visited the shores and the shallows. Some animals came to catch fish or feed on aquatic plants, while others fed along the shore. Some inevitably became prey of larger predators, such as the theropod that squatted in the mud so long ago. Rising silt-laden water or windblown sand filled the tracks of the animals. Over time, the accumulated sediments turned to stone, creating the Moenave Formation and preserving the dinosaur tracks forever.

Other ancient tracks in the area include sites in nearby Warner Valley and Washington City, as well as near Moab, Utah. Visit the regional interagency office on Bluff Street near the freeway exit for directions to sites on public lands administered by the Bureau of Land Management. For fossil track sites near Moab, visit the BLM’s Moab Field Office at 82 E. Dogwood St.

Be aware that BLM signing is sketchy at best. Equip yourself with good, detailed maps as well as their directional diagrams before setting out into sometimes remote locations.

Margo Bartlett Pesek’s column appears on Sundays.