GC1HFWA Life at Dinosaur Lake
Type: Earth | Size: Other | Difficulty: | Terrain:
By: Me & Bucky @ | Hide Date: 10/23/2008 | Status: Available
Country: United States | State: Colorado
Coordinates: N37° 37.069 W103° 35.802 | Last updated: 08/30/2019 | Fav points: 0

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This EarthCache will take you to the Picketwire Canyonlands Dinosaur Tracksite, the largest dinosaur tracksite in North America. Withers Canyon is the only allowable access to the canyonlands for the general public. Parking can be found near N 37 39.584, W 103 34.251. Hiking, non-motorized bicycles, and horseback are the only allowable access. It is a minimum 11 mile round-trip from the parking area to the tracksite and back, with 500 feet of steep elevation change at the beginning and end of the hike. Once you reach the tracksite, you will need to cross the Purgatoire River, which may be ankle- to waist-deep. Know your limits and plan your hike carefully as there is no overnight camping in the Picketwire Canyonlands. There is no drinking water available in the canyonlands, and at least one gallon of water per person should be taken with you. There is very little shade, so be prepared for the heat.

Picketwire Canyonlands is home to several rock art sites, as well as the Delores Mission and Cemetery. Please remember that cultural and paleontological resources on public lands are protected by law. Do not damage or remove cultural or paleontological resources. Making casts of the dinosaur tracks is not permitted without permission of the Comanche National Grasslands, U.S. Forest Service.

The Picktewire Canyonlands Dinosaur Tracksite is the largest dinosaur tracksite in North America. It is about one-quarter mile long and is located on both sides of the Purgatoire River in rocks of the Morrison Formation. The tracksite contains over 1300 visible tracks which make up over 100 distinct trackways.

The rock layers at this site help us to understand what conditions were like at the time the tracks were made. The limestone layers of the Morrison Formation show features such as mud cracks, which indicate that the layers formed next to the edge of a lake. This body of water was named “Dinosaur Lake” because of the large number of dinosaur footprints.

Several trackways of sauropods at this site show that these plant-eating dinosaurs walked side by side. This is one of the few trackways in the world showing herding behavior in dinosaurs. Tracks of the Allosaurus occur in all directions and seem to indicate that these meat-eating dinosaurs were more solitary. It is interesting to note that there are slightly more large meat-eating dinosaur tracks at this site than large plant-eating dinosaur tracks (about 60% to 40%).

To log this EarthCache, send me an email with the answers to the following questions: 1.) What other feature, besides footprints and mud cracks, helped to identify that these layers formed along the edge of a lake? 2.) The remains of what other lake dwelling animals have been found in the Morrison Formation at this site? 3.) What might it indicate when there are roughly equal numbers of tracks from plant-eaters and meat-eaters at this site?


Please consider posting photos of yourself, or the local geology, when you log this EarthCache. Photos can be an additional rewarding part of your journey, but posting them is not a requirement for logging this EarthCache, and is strictly optional.


The above information was compiled from the following sources:

Interpretive Sign at Site.

Pike & San Isabel National Forests, Cimarron & Comanche National Grasslands Website: Picketwire Canyonlands Dinosaur Tracksite http://www.fs.fed.us/r2/psicc/coma/palo/index.shtml and Comanche National Grassland – Picket Wire Canyon http://www.fs.fed.us/r2/psicc/coma/main/picketwireguide.shtml

Santa Fe Trail Scenic and Historic Byway, The Mountain Branch. Website: Picket Wire Canyon on Comanche National Grasslands http://www.santafetrailscenicandhistoricbyway.org/pwdino.html

2000. Lockley, M.G. et. al. A Guide to the Purgatoire Dinosaur Trackway, Excerpts from the Book Dinosaur Lake, Special Publication 40, Colorado Geological Survey, 1997; in Field Trip Guidebook A Dash with the Dinosaurs: A Mountain Bike Trek to the Purgatoire River Dinosaur Trackway and the Cretaceous-Tertiary Boundary Impact Layer of Southeastern Colorado, La Junta and Trinidad, Colorado.


Thanks to the Comanche National Grassland for allowing placement of this EarthCache!

10/12/2018 By M_Dundee
We visited the Picket Wire track site as part of a tour of Purgatorie Canyon given by the USFS to about 50 Volunteers for Outdoor Colorado (VOC) trail crew members. The next day the VOC trail crew restored the Withers Canyon trail between the canyon rim and floor by installing almost 50 new rock or timber steps. Our guide USFS Ranger Lynn brought along props to show which dinosaurs made which tracks. TFTC

10/21/2017 By Izzifix
What an awesome day with the guided tour to this place. Since i was a child i am a real fan of dinosaurs. It was very impressive to see all the tracks (and the real new ones, they are cleaned since 2 weeks ago) and all the other things like the natural window and the Ranch on this trip. A very interesting Earthcache, favorite point. TFTC and best regards from Switzerland, Izzifix

Answers sent.

10/21/2017 By HarvestMoon2
TFTE/C! FWIA, Izzyfix and I picked an awesome day to go down to Picketwire Canyon and take the dinosaur tour. Love learning about all the things these kinds of caches afford us. Izzyfix is sending required info for our group.

10/21/2017 By FWIA
Fantastic day to tour the Canyon and tracksite areas. The Forest Ranger was very thorough in explaining the history of the area. We were lucky enough to see 1 Tarantula while hiking back down from the Petroglyph site. The tracksite on the south side of the river had been recently cleaned so we were able to see some very newly discovered tracks. Thank-you for this E/C that piqued our interest in making the Canyon Tour. Izzifix has submitted the email with answers for us.

10/14/2017 By sassydil
Thank you for the earthcaches . I had been to Vogel Canyon previously and was glad to get back to the area to see the tracks.

10/14/2017 By COpackrat
The thing I like most about earth caches is that you learn so much that you had never even imagined! This was a prime example – the interpretive sign talked about how the dinosaurs lumbered along the edge of the lake!! This was unbelievable to me, but that's what it said. There must have been a lot of trees in the area back then, and so many environmental changes since that they never regenerated. I have included a portion of the interpretive sign, and an artist's rendition of a lumbering dinosaur. Thank you so much for the very educational cache. Answers on the way.