Utahraptor Ridge: ridge; elevation 5,238 ft.; on State Institutional Trusts Lands of Utah, 4 mi. NE of Klondike Bluffs, 4.9 mi. NW of Mollie Hogans; the name refers to the large number of Utahraptor fossils recovered at the ridge

Utahraptor Ridge: A Utah Landmark Named for a Landmark Discovery in Paleontology

Around 2001 a geologist named Matt Stikes discovered a bone at the site that would later become an an epic paleontological dig for Utahraptor fossils encased in sandstone that was once a quicksand trap. The dig was named the Stikes Quarry. Paleontologists from the Utah Geological Survey (UGS) then spent parts of 12 field seasons excavating at the Stikes Quarry, eventually exposing a nine ton block that is so dense with fossils, they dared not break it up for fear of damaging unique fossils and risking answers to some of the big questions that these fossils may hold. Utahraptor ostrommaysorum was recently named Utah’s State dinosaur. This block has bones from baby through adult Utahraptors, making the block very exciting to scientists researching ‘raptor’ dinosaur behavior and development.

Geologically, Utahraptor Ridge spans the late Jurassic Morrison Formation at its base, with the early Cretaceous Cedar Mountain Formation above, and a thin cap of Naturita Formation at the very top. The quarry site is in the Upper Yellow Cat Member of the Cedar Mountain Formation, where the fossiliferous sediments are near the shoreline of an Early Cretaceous lake. Conditions near the lake created a quicksand boil, and scientists believe the collapse of that quicksand is preserved as the massive sandstone block filled with Utahraptors, an iguanodontid dinosaur, and some other interesting fossils found so far.

With the generous help of the UGS, The Museum of Life at Thanksgiving Point, donors, and volunteers, the megablock was excavated, dragged out of the ground and into a lab at Thanksgiving Point in 2015. For five years, the Thanksgiving Point Museum of Ancient Life generously provided lab facilities for fossil preparation in a display setting dedicated to paleontology, education and outreach.

In early 2020, the megablock was moved to a lab created for the project at the Utah Geological Survey facility in Salt Lake City. Preparation and documentation of the block is precise and methodical, and preparation is expected to take many years. The project has already fostered scientific research and publication on the geologic specifics (taphonomy) of the quicksand trap. Check out additional information via the links provided below. If you go to visit Utahraptor Ridge, be prepared for rough roads and desert conditions. And please always report any fossils you might find to land managers.

View of the access track created to drag the gigantic block from the cliff to a waiting flatbed tractor-trailer

Trackhoe pulling a specially-constructed sled with the Utahraptor Megablock down the access track

Geologic cross-section of the Stikes Quarry site at Utahraptor Ridge

Learn more about the amazing fossils found at Utahraptor Ridge, and the ongoing preparation and research work:

Deep Time Treks page about Utahraptor

Utahraptor Project’s Facebook page

Preparator Scott Madsen’s Gofundme page for The Utahraptor Project

Utah Friends of Paleontology YouTube channel playlist of Utahraptor Project related videos

Utah Geological Survey article on dinosaurs from the Early Cretaceous Cedar Mountain Formation