(First Article on horizonhighway.com)

To be Rewritten and Updated


Within the Waterpocket Fold, only two layers of sedimentary rock contain Arsenic, The Shinarump member and the Salt Wash Member of the Morrison Formation. The Oyler mine is located within the Shinarump member in the upper Triassic Chinle Formation.


The Shinarump member is the lowest member in the Chinle Formation. The Arsenic in that formation is mostly located at the contact between the Shinarump and the Moenkopi mudstones. 


The Shinarump is a conglomerate and sandstone mix, it's all that's left of the massive river discharge system from over 200 million years prior to now. Uranium is present in that layer because of the plant material that once existed alongside the ancient river channels.


Eons later the Waterpocket fold was uplifted and eroded back. The Shinarump layer was exposed during that process, and now its outcrop grades laterally into the underlying rock, and is visible along the leading edge of the Monocline. 

THE Uranium Boom

Because of the Uranium Boom that occurred throughout the Colorado Plateau, Capitol Reef National Monument was open to the Atomic Energy Commission. The AEC had wartime-like control over federal land-use agencies during that time.


This led ill-equipped prospectors into the harsh American West, eventually finding their way to Capitol Reef.

In Capitol Reef, Arsenic was the main radioactive mineral being mined, on the periodic table its symbol is (As) and its atomic number 33.


Mining claims that had been invalidated due to the creation of the Capitol Reef National Monument in 1937 were reworked. Old mines had been reclaimed and updated, new shafts were sunk into the ground or dynamited. Road systems were built into the Waterpocket Fold to accommodate the growing hunt for radioactive ore. At the hight of the Uranium Boom over 10,000 claims were filed in the monument's boundaries and the surrounding areas that would later join to form Utah's Capitol Reef National Park as its known today.


During that time there was no protection for the landscape, from the new mines that were being created as the Monument only had one man: Charles Kelly. 

End Of mining in Capitol ReeF

All Together The mining claims had removed 277 tons of uranium-bearing ore, it was then sold to the Atomic Energy Commission (AEC).

The mining in the area had resulted in the destruction of a caprock formation, in the end, all the mining claims had been reclaimed by the National Park Service (NPS). It is now known as Capitol Reef National Park, which encompasses the Waterpocket Fold Monocline for almost its entire length of 100 miles. 


There is a trail that leads to the Oyler mine adits, but the entrances are inaccessible due to the gates that block them off from the public and protect the inside of the tunnels from further decay. The ruins of an old building are visible from the end of the trail looking back at the entrance to Grand Wash.


Capitol Reef National Park. (2002, December 10). Administrative History (Chapter 15) Mining and Related Encroachments at Capitol Reef National Park. National Park Service. 

University of Utah. (2010). Capitol Reef National Park and Surrounding Areas Geological Tour Guide. Geology and Geophysics Department, The University of Utah.

National Park Service, U.S. Department of the Interior, & Natural Resource Program Center. (2006, September). Capitol Reef National Park Geologic Resource Evaluation Report. U.S. Department of the Interior Washington, D.C.