Tag Archives: Colorado National Monument

Kodel’s Canyon

Geologic Time Scale

Growing up in Fruita, Colorado on Colorado’s Western Slope I had rich opportunities for exploration.  The area is amazingly diverse, offering the 10,000 foot elevation Grand Mesa to the east, the stark Bookcliffs to the north, and the spectacular red rock canyons of the Colorado National Monument just south of town.  All this surrounds the Grand Valley where I grew up. These areas and others were within short driving distance, with the Monument in bicycle range just across the Colorado River.

My friends and I used to take our .22s across the river and assault hundreds of rocks.  Our wandering took us across the National Monument boundary into Kodel’s Canyon.  Nobody went there in those days so we didn’t worry about having illegal guns in the park.  The canyon was smaller than the others, but we had the place to ourselves.  The approach is a deeply eroded plain of Dakota Sandstone from the river to the canyon.  The Cretaceous Dakota grades off to the Mancos Shale of the Grand Valley floor.

Kodel’s Canyon

That Mancos Shale is usually called Stinking Desert by many.  It is somewhat infertile unless well drained, and results in mostly barren gray flats.  Lots of barren gray flats from central Utah to Delta, Colorado.  With water and good drainage to carry the salt away, it can be farmland.  We would leave home on the valley floor and climb into the red rock Kodel’s Canyon.  At the mouth of the Canyon is the Kodel’s Canyon fault, where the Uncompahgre Uplift shoved all those Older Jurassic red rocks above the Cretaceous Valley.

Looking at the Grand Valley from Colorado National Monument

The bottom of the canyon is smooth rounded granite and schist geologists call basement rocks.  They are seldom found exposed on the Colorado Plateau, covered by thousands of feet of sedimentary rocks.  The time gap between those old basement rocks and the sedimentary rocks sitting on them is over a billion years.  It’s called the Great Unconformity, where all the rocks deposited during that billion years were eroded away.  This gap is found in many places worldwide, but there are also many places where the rocks missing in our canyon were deposited and remain to be seen and enjoy.  Think the Flatirons, Red Rocks, and the Garden of the Gods, all Cambrian.  Those rocks sit on Precambrian Gneiss and Schist 1.7 billion years old.

Those old rounded black rocks are great for climbing and we did it.  Today it’s called bouldering.  We didn’t have climbing ropes, so we used our .22s as climbing aids.  Dangerous?  Yes. Fun? You bet.

Among the guys I grew up with, only one had any injury running around across the river.  Jerry had a seriously sprained ankle.  The two guys with him helped him down to the road and help.  He exploited the ankle to excess.  At Boy Scouts we always played Capture the Flag after the meeting.  Jerry would hobble down to get the flag defying anyone to stop him.  I walked over and pushed him down.  I don’t think he ever forgave me.

The Bookcliffs and the River

 

Bookcliffs

Bookcliffs

The Book Cliffs are the neglected stepchildren of Western Colorado and Eastern Utah. That is somewhat ironic, because they stretch from Palisade and Mt. Garfield about 200 miles to Price, Utah. Rising about 1000 feet from the valley floor, they are the longest escarpment in the world. Above the Book Cliffs is a bench With the Roan Cliffs forming another escarpment  Behind the cliffs is the Roan Plateau, rising to about 8000 feet in elevation. With the wide change in elevation and precipitation from eight inches annually to around thirty, there is wide diversity in plant and animal life. There are energy resources as well. Natural gas, tar sands, oil, coal, and that huge deposit of oil shale.   The region is known as the Tavaputs Plateau.

The plateau is home to the Desolation Canyon Wilderness and due to the wide range in elevation and precipitation, a diverse range of plant and animal life. There are three reasons why the area is not very popular with visitors.

First, look south. Colorado National Monument, Arches, Canyonlands, Capitol Reef, Bryce Canyon, Zion, and Grand Canyon National Parks. There are the three mountain ranges and all that wondrous red rock carved into some of the best scenery on earth.

Next, accessibility. Douglas Pass is the only paved road in the vast area. The many dirt roads are accessible only as long as they are dry. Traditionally, the only people there were stockmen and the Utes on their reservation. In recent times there has been much energy-related activity that comes and goes.

The third reason? Shale. It is not only shale, there are layers of sandstone, even limestone. It’s all gray or shades of tan. Driving on the drab Mancos shale landscape of I-70, looking north you see drab cliffs. More of the same gray rock, just standing up. Roads built on that shale changes into some of the most slippery substances known after a rain or snow.. People are just not inspired to go there.

Growing up in Fruita, Colorado, I spent quite a bit of time in areas on either side of the Douglas Pass road, which was gravel and dust at the time. We had rancher friends, and deer season was a big social scene. It is wild, mostly empty country, home to lots of cattle, some sheep, a few ranchers, and a lot of wildlife. It is also famous for some of the most treacherous mud in the world. There are some sandstone lenses (we called them rims), but it is mostly shale, a former lake bottom that now sits thousands of feet above the Grand Valley, where the people live.

Colorado National Monument.  Bookcliffs on the horizon

Colorado National Monument. Bookcliffs on the horizon

I used to look at the Colorado National Monument with its red rocks to the south. To the north were the relatively drab Bookcliffs with the whitish Roan Plateau above them. Why the difference? The Monument is famous, with lots of information about the Uncompaghre Uplift lifting the Uncompahgre Plateau thousands of feet compared to the Grand Valley. As the plateau, erosion took the more recent rocks off, leaving the more resistant sandstone.

I thought some sort of uplift must have formed the Bookcliffs. Well, partly. When the entire Colorado Plateau was uplifted at the same time as the Rockies, The Colorado River just dug away, carrying the eroded rock to the sea. It is still digging, and is eroding those Bookcliffs to the north. Under the Bookcliffs are the rocks of the Monument. Someday the land will be fairly flat between Grand Junction and Craig. We won’t be around, however. These things take time.

So, the Colorado Plateau was uplifted and after that the Uncompahgre Plateau went up some more and wore down. The rocks exposed at the Monument are, a few miles north, well below the rocks of the Bookcliffs who are headed north as the river gnaws away. The Colorado River rules, it is just a bit slow.