Skyline Drive Trackway Site

In December of 1999, while going for a Sunday morning drive, William Kurtz, a paleontology student at The University of Colorado, made a remarkable discovery.  While walking along Skyline Drive , which is west of Cañon City , he was amazed to see what he thought were dinosaur tracks.  It was right above the road and visible, at least to a trained person.  Kurtz reported the find to Donna Engard, the curator of the Dinosaur Depot.  Together they went up to survey the tracks that he had seen.

The rock wall along Skyline Drive as it appeared before excavation began.  How many people, over decades of time, had looked at this and seen only rocks?

In February of 2000, with help from the city of Cañon City in closing Skyline Drive to work in secrecy, volunteers from the Garden Park Paleontology Society began to excavate the trackway site.  This involved as many as eighteen volunteers working with hammers, chisels, crowbars, picks, shovels and wheelbarrows to clear the tons of rock covering the tracks and other fossils.

….Some days it was Hot!

This is the discovery track after a lot of preparation work with hammer and chisel.  Now you see it…..

….Now you don’t!  After one too many blows with the hammer, it fell off into Bill Kurtz’s arms and was taken to the Dinosaur Depot where it is on display.

 So far, none of the others have fallen off.

In early April of 2000, the amazing find was announced to the press and Skyline Drive was reopened.  From then on the work became talking to visitors about what we were doing, as well as chipping away at more rock.  Since we were working most weekends, many repeat visitors came often to watch the progress. 

Jon Stone uses the new hammer drill on the Skyline Drive Trackway site to remove the overlying rock layers and expose the dinosaur tracks.

In order to preserve the value of the tracks for scientific study, molds were made of the “type set” tracks as well as some of the other unusual specimens that were found.  Here, Donna Engard, curator of the Dinosaur Depot, and volunteer Steve Martin apply layers of latex and burlap.  After this dried, the mold was removed and taken to the Dinosaur Depot where it was filled with plaster to create a cast of the footprint. 

This is a picture of the tracks that became the “Descriptive Set” which was used to define the type of dinosaur tracks that we found.  After many measurements of individual tracks and the stride length between them, as well as detail description, it was determined to be an Ankylosaur track known as Tetrapodosaurus borealis.  As you can see, the front foot or manus has 5 toes, while the back foot or pez has 4 toes.   These tracks were made during the early Cretaceous Period, approximately 107 million years ago.  During that time this area was on the edge of the Western Interior Seaway.  A group of dinosaurs were walking side by side through the mud along the edge of an estuary, probably eating the plants.  The tracks were then filled in by sand and plant debris, which hardened to preserve them as casts of the actual tracks.  After the sediments were deposited, the walls of the basin were raised by the Rocky Mountain uplift that tilted the rocks on edge.  This explains why they bulge out instead of being a depression like one normally thinks of as a “footprint”. 

In order to study the tracks, one of the most important details is exact measurement of each one. We started with traditional methods to gather every imaginable measurement of size and dimension of each track, plus stride angles and lengths between the tracks.  Here are three ways in which this feat was accomplished.  A.  A one-meter square metal frame marked in ½ meter squares.  B.  Part of a forty-meter by 4-meter grid marked in meter squares made out of non-stretch string.  C.  Since the tracks bulge out, we used a tape measure in conjunction with very large home made calipers that could measure around the bulge instead of adding the extra height to our measurements.

A few of the other fossils that were found during excavation of the trackway were: A. Tree roots.  B. Tree branches.  C. Mystery object that looks like a clam, but isn’t one.

Thanks to the Bureau of Land Managment (BLM) National Technology Lab we were also able to use very modern data using photogrammetry, which is the process of making precise measurements by means of photography, to get data for 3-D records of the tracks. Here Neffra Mathews of the BLM sights the camera, Donna Engard provides shade so she can see, Judy Stone steadies the tripod against the wind, and Pat Monaco keeps detailed records of the shoot.  Jon Stone supervises while Tom Noble of the BLM marks the next camera placement.

The black and white “targets” are reference points at known distances used in the final analysis of the measurements.

Neffra Mathews also arranged for Roger Moore and Chess Neff of 3-D Scan of Grand Junction to do a three-dimensional laser scan of the trackway.

Exact measurements to the “ targets “ from known points along the road were taken to add to the data for a precise photographic map of the trackway.

These images show photographic and laser scan data combined in different forms.  Each image has the distortions of the angle of the actual Trackway corrected to a flat image for pinpoint measurement of each track.

This is a topographic line map of the tracks.

This is a false color image that reflects the topography of the tracks with a 10 centimeter color break.

This image shows topographic lines on a color photograph.

Thanks to a generous donation from the Cañon City Rotary Club, we were able to purchase these explanatory signs and some safety improvements including a fence to separate visitors from the traffic on Skyline Drive .

The Trackway as seen on April 10, 2002 .

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