Colorado Bucket List: Picketwire Canyon Dinosaur Tracks

I’ve said it before and I’ll say it again: I’m a dinosaur snob. I can’t help it. I grew up in a state full of fossils, in a town with a pretty fantastic dinosaur museum. The bar was set really high when I was really young, so I’m not easily impressed. But this place was really cool!

Picketwire Canyon is located way out on the Colorado plains, carved into the landscape of the Comanche National Grassland by the Purgatoire River. The name Picketwire is actually an anglicization of Purgatoire, the name originally given to the river by French fur trappers. The name was chosen after a group of Spanish conquistadors died nearby and were not administered last rites, meaning they would be forever stuck in purgatory.

Most of our drive through the Comanche National Grassland was wide open, flat, and overflowing with tumbleweeds. But as we made our way south some topography began to emerge, first in the form of a row of bluffs and eventually as Picketwire Canyon. It was much larger and more expansive than we were expecting.

Located within Picketwire Canyon is the largest collection of dinosaur tracks in North America, and one of the largest in the world. Here, imprinted and preserved within the rocks of the Morrison Formation – the same layer that forms Garden of the Gods – are more than 1300 fossilized dinosaur footprints. 150 million years ago, this area was covered by water and home to various dinosaur species, including the enormous herbivorous apatosaurus and the smaller (relatively speaking, of course) carnivorous allosaurus and herbivorous ornithopods (duck-billed dinosaurs).

In more recent history, Picketwire Canyon and the Comanche National Grassland was the home of the Arapaho, Comanche, Kiowa, Jicarilla Apache, Ute, and Osage tribes (source). Later it was homesteaded by both white and Hispanic settlers.

We set out on our hike fairly early, hoping to beat the heat. There is almost no shade along the way, the predicted high for the day was in the upper 80s (~30°C), and we had nearly 12 miles (19.3 km) to hike. The trail begins by dropping about 300 feet (90 m) into Picketwire Canyon. Beyond this point it’s mostly flat and roughly parallels the Purgatoire River all the way to the track site.

At about the 4 mile (6.4 km) mark we came upon Dolores Mission, a Catholic church and cemetery built by a group of Hispanic settlers in the late 1800s. What remains of the small church has mostly fallen apart. A few grave stones are visible; most mark burial sites of young children. Entry into the cemetery is allowed, but please don’t touch or step on any of the structures or remnants.

Just shy of the dinosaur tracks is a replica of a shoulder blade from a partial apatosaurus skeleton that was unearthed in 2008 along with bones from a few other dinosaur species. The 8 foot (2.5 m) length of the bone indicates an animal that is estimated to have been 100 feet (30 m) long and weigh 40,000 lbs (88,000 kg)!

And finally, 5.7 long miles (9.2 km) after departing the trailhead, we reached the track site. There is a restroom here and informational signs explaining the site and the different tracks. I recommend taking a photo of the map before proceeding to the site so you know where to look and what you’re looking at.

The tracks are on both sides of the Purgatoire River; the river crossing was fairly easy to navigate. On the near side of the river is a collection of tracks from apatosaurus, ornithopods, and allosaurus. The allosaurus and ornithopod tracks are more difficult to discern; since they were smaller dinosaurs, the prints aren’t as deep or sharply outlined. Fortunately many of the tracks were filled with water, which made them much easier to see. The ones filled with dirt were less obvious and didn’t photograph very well.

On the opposite side of the river is a larger collection of apatosaurus tracks, including five parallel sets of tracks. These tracks in particular are noteworthy because the parallel rows provided the first ever indication that these animals traveled in groups.

We walked the entire track site (adding about half a mile to our hike distance) and then took a snack break on the edge of the river before heading back toward the car. The trail actually continues beyond this point for another couple miles (~3km) to Rourke Ranch, built by white settlers and operated for 100 years from 1871-1971. Given how far we’d already hiked, we opted not to make the trek.

Though it was only April, the sun was blazing during our return hike and it was HOT. I would never ever ever do this hike in the summer. It would be so easy to become dehydrated and develop heat stroke. And don’t forget… after hiking 11.5 miles (18.5 km) you still have to climb 300 feet (90 m) up out of the canyon. It was the most daunting 300 feet of my life. Okay so maybe I’m being a little dramatic. But in the moment, hot and sweaty, with tired muscles and protesting feet, it sure felt that way.

And this wraps up our whirlwind three day weekend. We checked two more high points, two national historic sites, and these dinosaur tracks off our to-do list, not to mention a fairly thorough driving tour of the eastern plains. And so, sweaty, exhausted, and covered in dust, we headed out of the Comanche National Grassland and began the drive back to Denver.

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Read more of my Colorado Bucket List series here.

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The Important Stuff:

• Getting there: this hike departs from Withers Canyon Trailhead in Comanche National Grassland; the trailhead is at the end of a dirt road between Highway 305 and CO Route 109
• Fees and passes: none
• Hiking: round-trip to the dinosaur tracks is 11.9 miles (19.2 km) with 405 feet (123 m) elevation gain… most of which is in the final climb up out of the canyon
• Where to stay: dispersed camping is allowed at the trailhead in designated sites only. No camping or backpacking is allowed in Picketwire Canyon. The closest town is La Junta (we stayed at the KOA there)
• Other: Be ready for exposure to the elements; even in April it was in the 80s, sunny, and dry. I drank 2.5 L of water and was still thirsty. And we both got sunburned. There’s no phone service or any amenities out here so really be prepared to be on your own for a full day.