Stegosaurs have played an important role in Fremont County paleontology. The Morrison Formation in the Garden Park Fossil Area just north of Cañon City has produced four Stegosaurs and, unlike most other Morrison localities which have been productive only near the middle of the formation, Garden Park has produced dinosaurs from the bottom to the top of the Morrison Formation.
The first Fremont County Stegosaurus, Stegosaurus armatus, was discovered at the Marsh-Felch Dinosaur Quarry in 1884. The next three Stegosaurs were all Stegosaurus stenops.
In 1885 a nearly complete and articulated specimen was found in the Marsh/Felch Quarry. This specimen, the holotype (the single specimen designated as the type of a species by the original author at the time the species name and description was published), has been on display at the National Museum of Natural History (Smithsonian) in Washington D.C. for over one-hundred years and has been humorously termed the “road kill” based on the remarkable condition in which it was found. It was excavated in 1885-86 by Civil War veteran Marshall P. Felch who worked for Professor Othniel Marsh of the Yale Peabody Museum. It was this specimen in large part which led to the first major paper by Othniel Marsh that fully described and illustrated a Stegosaurus specimen. Today an interpretive trail in Garden Park leads to an overlook of the quarry location.
In 1937, local high school teacher F.C. Kessler and some of his students found and excavated the third Fremont County Stegosaur which has been on display at the Denver Museum of Nature and Science (DMNS) since 1940, and today can be seen in Prehistoric Journey. Based on this specimen, the Stegosaurus became the Colorado State Fossil in 1982.
The fourth and virtually complete specimen was found by Brian Small and excavated in 1992 from the Small-Carpenter Quarry in Garden Park by DMNS. This fully articulated skeleton, lacking only the shoulders and front legs, was complete with back plates, articulated tail with attached spikes, and osteoderms (bony scales) in place under the neck. This good fortune enabled paleontologists to finally confirm the exact placement of the bony double row of back plates as alternating, the tail spikes as horizontal, and the osteoderms as located under the neck. Because the bones were all joined together, and separation was impossible, a decision was made to remove the Stegosaur in three sections (skull area, body, and tail). A Chinook helicopter supplied by Fort Carson was needed to airlift the body jacket weighing 13,000 pounds from the remote location. The skull is on display in Prehistoric Journey at DMNS (the body and tail reside in DMNS collections), and a full-sized replica is located in the DMNS paleo lab and also on display at the Royal Gorge Regional Museum in Cañon City.
The 1885 and 1992 specimens have the only two complete Stegosaur stenops skulls ever found.