On the Island in the Sky Mesa in Canyonlands National Park is an impact crater measuring 5km across.   The impact was about 65 million years ago.   The area surrounding the dome has horizontal layers of sandstone, but the layers surrounding the crater have been deformed into a syncline and some layers are nearly vertical in orientation.  In the center of the crater are rocks that would usually be found 1000 feet lower in the ground.   The prevalent theory is that a meteor(ite) about 1/3 of a mile across impacted the site and created a large explosion sending debris into the atmosphere.   The impact broke the layers and caused instability which have eroded and collapsed and been partially scoured away.     In the unstable phase, rocks from below were thrust upward and over time the region settled into what we see today.

We hiked around the Dome on the Syncline Loop Trail one day, an 8.3 mile route.

On another day, we went up the Upheaval Dome Viewpoint Trail (1 mile return).   We continued along the west rim along the slickrock as far as we could.   Back at the viewpoint (a 2.5 mile route), we then scrambled up rock onto the south rim and continued east until we chose to loop back to the parking area (about 4.5 miles total).   This geological feature is both interesting and scenic and worth a couple of hours of exploration.