Poison Spider Dinosaur Tracks, UT

The area around Moab, Utah, is one of the most beautiful places on earth. Rolling expanses of red slickrock cover the place, while the La Sal mountains rise to the east, and the Colorado River cuts down through it all, exposing amazing geology and creating astounding side canyons. Millions of people every year come to visit the area, to backpack, hike, mountain-bike, 4x4, raft, or simply see the sights of one of Nature's greatest displays.


Just downriver from Moab, at the foot of Poison Spider mesa and at the bank of the Colorado River lays a unique opportunity to explore the prehistoric past of the area in one easy hike. The Colorado River, cutting downward through the Jurassic-age Entrada Sandstone as it makes for Cataract Canyon, has exposed evidence of some of the area's earliest visitors.The Entrada Sandstone was deposited during the early-middle Jurassic Period, and was an environment dominated by large, mobile dune fields. Some of the best preserved of these dune fields lay inside nearby Arches National Park, along the park road. In between these dunes, however, were seasonal lakes and some streams. It was hear, in this ancient desert, that life flourished. Ancient crocodiles prowled the streams, while theropod dinosaurs, like Dilophosaurus wetherilli and Coelophysis kayentakatae visited the water holes to drink or hunt. At the southern edge of Poison Spider Mesa, evidence of some of these visitors still exists.

From the Poison Spider Trail parking area, head east-northeast. There is a large pile of boulders heading upslope towards the cliff face. It is here where the majority of the tracks are located. Some previous tourists have chalked over some of the dinosaur tracks, making them easier to see. Please do not continue this practice, as it degrades the footprints over time.

From the dinosaur footprints, head towards the cliff face. You can see a slab of rock that has separated from the main section of cliff. It is here that many petroglyphs from the Fremont culture can be seen, both behind and next to this slab. Some are truly strange, like a giraffe-goat, and two-headed rams. Others are more typical fare, like bighorns and figures. Spend some time exploring here, before returning to your vehicle. Keep an eye out along the way for more dinosaur tracks.

For more fun, on the way back into Moab, make sure to see the "Indian Writing", a large collection of Fremont petroglyphs along the cliff face. The area is signed, but parking is limited, so be careful. There is also the remains of a dwelling that was destroyed during road construction; all that remains are the beam holes up on the cliff face.

There is no water on either portion of this hike. Although the Colorado River is nearby, it is also immediately downstream from the old Atlas Uranium Mill; think twice about drinking it, even with treatment. A better bet is to fill your bottles back in Moab.

2008-01-28 PaleoRob