Tuesday, November 3, 2015

The San Rafael Swell, Utah

Brad and I retrace our initial drive across Boulder Mountain (between Capitol Reef National Park and Escalante, elevation about 10,000 feet) to an area in Utah known as the San Rafael Swell, or to locals as "The Swell". Geologically, it's an anticline; in layman's terms it's a bump on the earth. The earth and rock have been pushed up by underground pressure into a dome stretching 80 miles north-south by 35 miles east-west. As the top of the dome erodes, the multiple layers of sediments and rock are exposed in almost vertical stripes around the edge. These vertically exposed ridges are referred to as the San Rafael Reef because the rock formations resemble a reef. The Swell is criss-crossed by 4x4 roads, creeks, pioneer ruins, old mines, and slot canyons. Another playground for us. Our friend, Dolores (Dr. D), actually drives down from Ottawa, Canada to spend a little over a week with us, and we chose this area to begin the tour.
Goblin Valley State Park

We camp (for free of course) just outside of Goblin Valley State Park on federal land (BLM) beside the towering rock formation in the Reef known as Temple Mountain. As our first tour stop, we hike through the hoodoos, or goblins, in the state park. Mostly, Dolores and I just chat throughout the walk, but as a Ph.D. Geologist, she greatly appreciates the landscape of weathered, spooky shapes. BTW, some of the spoof Tim Allen movie, Galaxy Quest, was filmed here.
Little Wild Horse Canyon

What I consider our first real hike with Dolores, about 3-4 miles round-trip through Little Wild Horse Canyon, probably the prettiest slot canyon in the Swell. This is the narrowest part of the slot, with beautifully textured walls.

The angular striations rising out of the sandy stream-bed are just part of what gives this canyon its wonderous beauty. You can imagine the layers of sand being deposited over millions of years; mixing with minerals like iron, manganese, and silicates to colour them with hues of orange, purple and pink; compressing into stone under the massive weight; tilting upwards with geological forces deep within the earth; and finally eroding over the millennia into the undulating waves, alcoves, and variety of shapes we see today.

Around each corner is a new surprise. Here, holes have been ground into the walls by swirling stones deposited during flash floods. You can almost see the power of the water after heavy rains squeeze the stream through these narrow walls. Rains 50-100 miles away can cause a flash flood in a canyon like this which are best avoided if rain is possible in the vicinity.
Cathedral Valley in Capitol Reef National Park

We travel Cathedral Valley in the northern backcountry of Capitol Reef National Park backwards, from the south entrance via the Cainville Wash Road to the northwest. We lunch in Lower Cathedral Valley beside Temple of the Moon with a view of Temple of the Sun in the background. These clay/sandstone "cathedrals" rise some 400 feet from the desert floor.

Glass Mountain is a strange heap of selenite crystals a few hundred feet from Temple of the Sun. What's interesting about the crystals is that they are arranged helter-skelter, unlike how they should form.



Along the drive, Dolores identifies these dykes, formed eons ago when magma fills cracks deep in the earth or often underwater. They are slower to erode than the surrounding softer sandstone and clay formations.

Another interesting feature as we make our way across the valley from Lower to Upper Cathedral Valley is the Gypsum Sinkhole. Our resident Dr. D, geologist extraordinaire, guesses that a layer of gypsum lay several hundred feet beneath the surface and might have been dissolved by an underground stream, causing the top layer of stone to collapse leaving this hole some 200 feet deep and 50 feet across.

A view of Upper Cathedral Valley from the overlook at the top of a very narrow, twisty 4x4 road leading back to the highway. Can you spot Brad atop the fin in the foreground?

The road back to the highway on the northwest side leads us over Thousand Lakes Mountain where the fall colours are at peak. These are aspens whose bright yellow leaves contrast the intermixed evergreens like day and night. Splendid beauty and a welcome sip of fall after the hot, arid valley below.
Capitol Reef National Park

Brad and I have been through Capitol Reef NP a few times, but since we're nearby, we tour the highlights for Dolores. Here we are driving through Capitol Gorge at the end of the scenic drive from the Visitor Center. This wall has the look of swiss cheese (not a geologic term!) A short hike at the end of this dirt road takes us to the Pioneer Register, canyon walls where passing pioneers preserved their names or initials and the date they traveled through.

Still in Capitol Gorge, this wall is a spectacular example of desert varnish. The black stripes on the sandstone are thought to be formed over thousands of years by living bacteria and fungi deposited by seeping water. Sometimes, desert varnish covers and entire wall and it gleams in the sunlight just as if it was varnished.

Dolores and I hiking in Grand Wash which narrows about half-way between its access from Cathedral Gorge and the Fremont River. Not narrow enough to be a slot canyon, but an enjoyable 2-mile hike anyway.

3 comments:

  1. well this is just too fabulous for words. thank you for sharing all these spectacular photos and meaty interesting words.

    ReplyDelete
  2. Fond memories of San Rafael Swell...that's where we met Alice & Robbie the year after you met them... parked in the same locations :) Have a meet-up planned with them this winter... maybe it will work for you two to join in. Would be a fun gathering!

    ReplyDelete