Cleveland-Lloyd Dinosaur Quarry (CLDQ) at Jurassic National Monument contains the densest concentration of Jurassic-aged dinosaur bones ever found. Over 12,000 bones (belonging to at least 74 individual dinosaurs) have been excavated at the quarry. Cleveland-Lloyd Dinosaur Quarry has helped paleontologists learn a great deal about the Jurassic period, yet the site presents at least as many mysteries as it helps to solve. Curiously, more than 75% of the bones come from carnivores, primarily Allosaurus fragilis. With more than 46 individual specimens of Allosaurus, scientists have been able to deduce much about how Allosaurus aged and compare individuals to better understand intraspecies diversity. Yet the sheer density of bones proposes many questions. How did the carcasses of so many animals end up in one place, and why are most of them meat-eaters? While many good hypotheses have been presented, they all still have major flaws - the mystery has yet to be solved.

Source: BLM Website (March 2023)

Establishment Jurassic National Monument — March 12, 2019

For More Information Please Visit The OFFICIAL BLM WEBSITE

The contents of brochures, site bulletins and trading cards (denoted with a colored caption) can be viewed by clicking on the cover. Most modern-day brochures, however, are cover only (denoted by a white caption) due to photograph copyrights. These items are historical in scope and are intended for educational purposes only; they are not meant as an aid for travel planning. The dates under each brochure do not reflect the complete range of years that a particular brochure was issued.

Cleveland-Lloyd Dinosaur Quarry Date Unknown	Date Unknown
Rock Walk Nature Trail Guide Date Unknown

Allosaurus fragilis: A Revised Osteology (James H. Madsen, Jr., Utah Geological and Mineral Survey Bulletin 109, August 1976)

Annual Manager's Report: 2021, Jurassic National Monument (Kyle Beagley, Dana Truman and David Baker, 2021)

Annual Manager's Report: 2022, Jurassic National Monument (David Baker, Casey Dooms and Dana Truman, 2022)

John D. Dingell, Jr. Conservation, Management, and Recreation Act—Establishment of the Jurassic National Monument (Public Law 116-9, March 12, 2019)

Junior Explorer: Cleveland-Lloyd Dinosaur Quarry (Tara Callagy, undated)

New data towards the development of a comprehensive taphonomic framework for the Late Jurassic Cleveland-Lloyd Dinosaur Quarry, Central Utah (Joseph E. Peterson, Jonathan P. Warnock, Shawn L. Eberhart, Steven R. Clawson and Christopher R. Noto, PeerJ, June 6, 2017)

Taphonomic patterns of a dinosaur accumulation in a lacustrine delta system in the Jurassic Morrison Formation, San Rafael Swell, Utah, USA (Janet Bertog, David L. Jeffery, Katherine Coode, William B. Hester, Rath R. Robinson and John Bishop, extract from Palaeontologia Electronica,Vol. 17, Issue 3.36A, October 2014, ©Society for Vertebrate Paleontology)

The Cleveland-Lloyd Dinosaur Quarry: Window to the Past (Wm. Lee Stokes, 1985)

The Dinosaur Death-Trap of the Cleveland-Lloyd Quarry, Emery County, Utah (Dean R. Richmond and Thomas H. Morris, extract from The Continental Jurassic, Museum of Northern Arizona Bulletin 60, 1996)

The Late Jurassic Cleveland-Lloyd Dinosaur Quarry as a Drought-Induced Assemblage (Terry A. Gates, extract from Palaios, Vol. 20, 2005, ©Society for Sedimentary Geology)

The Taphonomy of the Cleveland-Lloyd Dinosaur Quarry, Upper Jurassic Morrison Formation, Utah: A Re-Evaluation (Adrian P. Hunt, Spencer G. Lucas, Karl Krainer and Justin Spielmann, extract from Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin 36, 2006)

What Killed the Dinosaurs in Utah's Giant Jurassic Death Pit? (Riley Black, extract from Smithsonian Magazine, July 10, 2015)