Dinosaur Tracks

Research has uncovered that 150 million years ago two types of dinosaurs, Allosaurus (or related theropods) and Brontosaurs left their foot prints. The tracksite extends 1/4 of a mile and is considered to be the largest continuously mapped site in North America with over 1,300 footprints in four different layers of rock.

Complete map of visable Dinosaur tracks

The longest continuous, exposed dinosaur track in the world is found in the bed of the Purgatory River, and this track provided the first evidence of social oganization among family groups in dinosaurs.

Forty percent of the tracks were left by a massive four footed plant eater, the Brontosaurs accompanied by younger Brontosaurs heading west along the shoreline. The shores contained algae, clams, snail, crustaceans and fish. Parallel trackways indicate that several of the smaller brontosaurs were traveling as a group heading west along the shoreline. This evidence of social behavior among "juvenile" brontosaurs is the first of its kind from the Morrison Formation. The other sixty percent of the tracks were left by the Allosaurus. They were two footed, three toed and ferocious meat eating scavengers hunting in packs.

The impact of these dinosaurs is evidenced by the fossils of trampled plant stems and a collection of several dozen clams that were killed by the heavy footfalls of brontosaurs. The tracksite is the largest and most important of the 30 or more Morrison tracksites known. It has more tracks than all of the others combined. The area is rich in geological and historical resources and is a haven for wildlife. Please help reserve this area and keep it beautiful. The Army will only put a fence around this area, which will not stop the bombs!

Geologic explanation of the Dinosaur Tracks, click here

Map of unseen tracks in the streambed, found with Ground Penetrating Radar:

The readout from the Ground Penetrating radar of the tracks under the rock:

The geologic formation the tracks are found within:

Here's how the Army takes care of these invaluable tracks: by landing a helicopter on top of them!

Dinosaur Tracks guide

Satellite map

Roadmap with landmarks

Forest Service map

Topo map (for printing)

Page 2 on Dinosaur Tracks

The 2002 Schumacher and Stemberg Museum dig in Picketwire canyon
2002 Dino Dig page 2

2002 Dino Dig page 3

Canyons of Southest Colorado

1996 Vertebrate Peleontological Preservation Act (Baucus Bill)

1996 Fossil Preservation Act

Forest Service website on PicketWire Canyon

For more information about Picketwire Canyonlands Dinosaur Tracksite

Gillette, D.D. and M. G. Lockley, editors. 1989. Dinosaur Tracks and traces. Cambridge University Press, Cambridge, England.

Lockley, M. G., Houck, K., and Prince, N. K. (1986) North America's Largest Dinosaur Tracksite: Implications for Morrison Formation Paleoecology, Geological Society of America Bulletin, 97(10): 1163-1176.

Lockley, M. G. (1991) Tracking Dinosaurs: a New Look at an Ancient World, Cambridge University Press, 238 p.

Lockley, M. G., Fillmore, B., and Marquardt, L. 1997 Dinosaur lake: the story of the Purgatoire Valley dinosaur tracksite area. Colorado Geological Survey, Special Publication 40. 64p.

Prince, N. K., and Lockley, M. G. (1989) The Sedimentology of the Purgatoire Tracksite Region, Morrison Formation of Southeastern Colorado, Pp. 155-164, in Gillette, D. D., and Lockley, M. G. (eds.), Dinosaur Tracks and Traces, Cambridge University Press, 454 p.

Dinosaur tracks and other fossil footprints of the western United States
    Lockley, M. G.

For all dinosaur enthusiasts, rock-hounds, and tourists, this is the definitive guidebook to the paleontological treasure trove of fossil footprints in the western United States. Concentrating on the rich fossil life of the Colorado Plateau region-including parts of Utah, Arizona, and New Mexico-Martin Lockley and Adrian P. Hunt tell the story behind a track record that extends back in time some 300 million years. Distributed by Syndetic Solutions, Inc.
Footprints and trackways can provide useful information about the animals that left them. Tracks complement bones and enable paleontologists to learn about behavior, speed of movement, and so forth. Although some prints can be assigned to an animal known from its bones, in most cases, assignment is made to a broader group. This is the third book largely or exclusively on tracks that Lockley has published in the last six years (Tracking Dinosaurs, 1991; and Dinosaur Tracks and Traces, ed. with David D. Gillette, CH, Feb'90). The present volume focuses on western US dinosaurs but also covers Paleozoic tracks and those of some Cenozoic birds and mammals. The book is organized by geologic periods and examines, in detail, specific sites and their trackways. The introductory chapter provides a brief explanation of how tracks and footprints are formed and preserved, and some of the difficulties of understanding this fossil record. Much of the latter material was covered more substantially in the 1989 book. Within each chapter specific sites and their prints are discussed and comparisons made with other sites. The last chapter considers questions about interpretation of paleoenvironments, biomass of species in the track area, changing numbers, and kinds of trackways over time. An appendix lists places to see trackways (in museums and in situ). Upper-division undergraduate through faculty.

A guide to dinosaur tracksites of the Colorado Plateau and American Southwest
Publisher: Dept. of Geology, University of Colorado at Denver,
Pub date: 1986]
Pages: 56 leaves. :
Copy info: 1 copy available at Carnegie-Special Collections.
1 copy total in all locations. 

Penrose Library on Cascade in Colorado Springs:

Carnegie-Special Collections Copies Material Location
567.910979 L816G 1 SC Book Spec Coll History Book Stacks

The eternal trail : a tracker looks at evolution
    Lockley, M. G.


Lockley, a paleontologist and geologist with the University of Colorado, demonstrates how the art and science of tracking offers insights into the biology and evolutionary history of a diverse array of extinct animals, providing in the process an approach to tracking that emphasizes the self-organizing principles at work in the natural world. Annotation copyrighted by Book News, Inc., Portland, OR Distributed by Syndetic Solutions, Inc.


Dinosaur footprints and other fossilized tracks are "the sheet music of the biosphere," writes University of Colorado geologist Lockley (Tracking Dinosaurs) in this uneven mix of science and mysticism. Lockley's professional expertise lies in interpreting fossilized traces and tracks; the best parts of this volume ably describe the process of drawing inferences from prints, fossil and otherwise. Were the odd tracks in South Korean rocks left by baby brontosaurs? Do Bigfoot's alleged tracks prove him (a) not a hoax and (b) a recently extinct giant ape? Lockley, guardedly, answers "yes" to all three questions. He also provides modest insight into the world's small community of trackers--those scientists who study footprints. But readers expecting a short, reliable course in fossils and feet might be taken aback by the author's embrace of non-scientific beliefs. For Lockley, biological evolution has a spiritual goal, "hands and feet are the mirrors of the soul," and "we might infer from their foot shape that ancient Celts were more intuitive and mystical, whereas Saxons [were] more practical and down to earth." Lockley's overall thesis amounts to a decidedly non-Darwinian view of life: he believes that a "cyclic pattern of ascending and descending forces... characterize the growth cycle of all individuals, species, and larger groups," a pattern that points human beings toward "cosmic consciousness." Arguing for more research into palm-reading, he asks, "Why should minuscule genes tell us more about ourselves than our entire hands?" (Ask any geneticist.) Some readers will welcome Lockley's sincere (and well-footnoted) attempts to link his special skills to his spiritual hopes; others will deplore his refusal to distinguish between testable and untestable hypotheses, "biosphere and noosphere," paleontology, anthropology and religion.

University of Colorado professor Lockley, an undisputed international expert on paleoichnology (the study of fossil tracks), presents a truly astonishing array of fossil track facts and lore: dinosaur tracks mistaken for human tracks by creationists; tracks attributed to the Virgin Mary's mule; tracks found in the paving stones of a Brazilian village and saved by a clever paleontologist masquerading as a city worker; a Mark Twain satire attributing ground sloth tracks to the Nevada Territorial Legislature; tracks that imply dinosaur herding, migration, and predation; and footprints on the moon. All of this pours forth in an enthusiastic though oddly New Age catalog; Lockley seems unusually credulous for a respected scientist. He expresses belief in palmistry, Bigfoot, and an unconventional conception of evolution. Thus, while Lockley's tracking science is impeccable and his writing engaging, his flights of fancy make this book less suitable than his previous works for students, who may not be able to sort out science from pseudoscience.

Paleontologist Lockley studies fossilized footprints (ichnology), the petrified record of which extends back a half billion years. Lockley, informing readers of the great strides his field has made in matching footprints to species, stretches the point further to infer the extinct animal's shape and behavior from its prints. And that line guides his enthusiastic chronology of life since the Cambrian explosion, when sea critters like trilobites began to leave their imprints. Lockley divides geologic time into "acts" and stage manages the entrances of traces left by their characters: foot-wide tracks of gigantic millipedes of the Carboniferous period, patterns left by the reptiles of the Mesozoic era, one a trackway showing herd behavior in dinosaurs, for example, and on through time to the Laetoli trackway of bipedal hominids to boot prints left on the moon. Lockley's work might have benefited from a heavier editorial hand, excising digressions (one, into yin and yang ethereality), yet he presents a wealth of observations about the contributions ichnology makes to paleontology.

Lockley is the world's best known "tracker," especially of dinosaurs and other ancient animals; his book is a personal survey of tracks in the fossil record and their place in evolutionary theory. Some parts are first-rate, especially those in which Lockley describes the investigatory history of mysterious trackways and the discovery of unusual trails, such as those of pterosaurs. Lockley shows a remarkable and praiseworthy caution in his interpretation of dramatic trackways, such as those that are elsewhere purported to be of dinosaur confrontations. Only he could describe in such clear prose the limits of evidence in track interpretations. Unfortunately this book is also filled with superfluous philosophical digressions and questionable detours. "Spirits" of long-dead animals appear all too frequently, as does the male "yang" of the foot penetrating the female "yin" of the Earth. Lockley appears to think palmistry may have scientific validity, and that the "noosphere" of Teilhard de Chardin is the next "layer of complexity" above the biosphere. Tracks eventually embrace all of history--even the big bang has left a "big footprint." An editor should have trimmed away these excessive and unwarranted speculations to better expose the superb tracking book hidden inside. General readers; undergraduates through professionals.

To Resurrect a Brontosaur: Picketwire Canyonlands Sauropod Excavation

Comanche National Grassland, Pike-San Isabel NF, Colorado, 2001-2002

by Bruce A. Schumacher, FS Paleontologist

In May 2001, the Comanche National Grassland hosted the second-ever paleontological PIT project. Twelve volunteers gathered in Picketwire Canyonlands, a rugged, deeply carved valley in southeastern Colorado renowned for its wealth of historical and prehistoric archaeology. But there are much older "tales" in this river valley. The canyonlands are also home to the largest dinosaur track site in North America, with more than 1,300 footprints of late Jurassic dinosaurs exposed in limestone layers along the Purgatoire River. The walls of the valley are composed of rock layers dating to the Jurassic-aged Morrison Formation, known to produce dinosaur skeletons in many parts of the Rocky Mountain West. Although only fragments of dinosaur bone had been noted in the canyonlands prior to the 2001 PIT project, the volunteers nevertheless spent a hot, exhausting week combing the canyon walls searching for fossils. Very little of real significance was discovered during the project until the last day, when George Sweeney, a volunteer from Ogden, Utah, emerged from a remote canyon and straggled back to the group gathering for lunch. George produced a handful of petrified wood from his backpack and showed it to me. Amazed, I told George that this was not petrified wood but, rather, dinosaur bone. When I asked George if there was more, he said, "The ground was covered with it." Thus began the discovery and investigation of the second-most-significant dinosaur site so far known in Picketwire Canyonlands (the first being the track site). The crew returned to Sweeney's discovery site and found enough dinosaur bone on the surface to fill two ice chests. More important, an ischium (pelvis bone) was noted emerging from the shale layers, and a little scratching showed that the bone continued beneath the surface. All were excited to begin excavation of the skeleton the following year.

In June 2002, the original PIT crew returned to the discovery site with brushes and trowels in hand. A quarry began to take shape, with assistance from the Sternberg Museum of Natural History in western Kansas. This year, the crew uncovered major portions of a large sauropod ("brontosaur") skeleton, including two vertebrae, five ribs, a partial femur, and several pelvis bones. Because the bones are so large, only a few can be uncovered each year, and we anticipate this quarry (along with those yet undiscovered) will keep PIT volunteers busy for many years to come. We look forward to uncovering more of this beast ("Woody") in future PIT excavations. We will also host additional PIT projects to search for more dinosaur skeletons. At present, we have surveyed only a small percentage of the potentially fossiliferous areas in Picketwire Canyonlands. Who knows what other beasts are out there waiting to be discovered!

Page 2 on Dinosaur Tracks