Saturday | April 11, 2026
Geological Glory
of The San Rafael Swell
Led by geologists Paul Anderson and Tom Chidsey
The San Rafael Swell is a showcase of Colorado Plateau geology. This large, anticlinal feature formed due to Laramide mountain-building compression during the Cretaceous through early Tertiary (65 to 45 million years ago). Uplift and erosion of the Swell have created a colorful array of sedimentary rocks about 6,900 feet thick, ranging in age from Permian (280 million years ago) through the Cretaceous, exposed in spectacular cliffs along cuestas, mesas, and deep canyons.
These rocks were deposited in a wide range of environments including dune, floodplain, river, braided stream, delta, swamp, tidal flat, and shallow marine, now long gone.
This full-day trip is excellent for anyone who loves scenic dirt road driving. Expect short hikes to outcrops of interest and a full day of learning!
See below for important trip information.
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Participants must drive their own cars.
This long loop will traverse some dirt roads with a few rough spots.
A moderately high clearance vehicle is required, but not 4- or all-wheel drive.
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A full tank of gas.
Lunch, water, sturdy shoes, binoculars, camera, and snacks.
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Paul Anderson and Tom Chidsey
Paul Anderson has been a geologic consultant for nearly 40 years and a past resident of Emery, Utah, where he and his wife Mary Ann are active in the local community. Paul is an expert on the Cretaceous geology of Emery County including its coal and gas resources as well as many other areas of the state.
Tom Chidsey is an emeritus geologist from the Utah Geological Survey where he worked as a petroleum researcher for 31 years and 13 years prior in the oil and gas industry of Utah and Texas. Both Paul and Tom have served as presidents of the Utah Geological Association and have been awarded the prestigious Lehi Hintze Award for Outstanding Contributions to the Geology of Utah.
The east flank of the San Rafael Swell. Photo courtesy Tom Chidsey.