Category Archives: Green River Formation

The Enigma of the Colorado Plateau

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Although I have lived somewhere along Front Range Colorado most of my life, I still think of the Colorado Plateau as home.  I am dedicated to the region because of its Geology.  All that rock is just sitting there looking at you.  There aren’t too many plants to get in the way.  I grew up looking at the red rock of the Colorado National Monument just across the river from home.

Thing is, the red rock is mostly from the Mesozoic.  There is a lot of boring buff colored rock from the Cenozoic, notably the Green River Formation.  The Green River Isn’t much to look at, but it has a huge present day impact.  Look at my piece on the Formation in Categories.

I am currently interested in the time after the Green River Formation was deposited.  The literature on this time on the Plateau is relatively sparse, mostly because it was more a time of erosion, not deposition.  A large part of the deposition was in fresh water lakes with only remnants of the sediments today.  Those red rocks forming canyons and arches get all the press.

For most of its existence, the Colorado Plateau had no outlet to the sea.  Then, a bit less than six million years ago. The Colorado River decided to head for  Baja California.  There have been lots of explanations for this happening, but they boil down to elevation change.  The Plateau ended up higher than the Basin and Range province to the west.  That area was once a highland, but big tectonic forces changed everything. Then, a stream eroding east carved enough of a canyon to capture the Colorado Plateau drainage which became the Colorado River.

As you are aware, the Pacific Plate is colliding with the North American plate.  The collision is not at right angles, the Pacific Plate is headed northeast.  As it slides along, it pulls on the North American plate, somewhat pulling it apart.  The area east of the Sierras known as the Basin and Range is being stretched.  As it stretches, big blocks called grabens drop down, leaving mountain ranges between them.  The area ended up lower than the Colorado Plateau.

The Basin and Range Stretched

It’s not entirely clear if The Plateau was uplifted during this time by remnants of the same forces responsible for creating the Rocky Mountains.  It seems to me the uplift was earlier, but my reading on the issue is not conclusive. The fact is the Plateau ended up higher than the Basin and Range.  Erosion then began digging away in the area west of Grand Canyon, hooking up with the internal drainage of the Plateau.  Canyon cutting began.

All those spectacular canyons are younger than six million years.  An interesting sidelight is that the stretching of the Basin and Range continues, and the Colorado Plateau is slowly rotating clockwise.  The question for me is why is the Plateau still in one piece?  Compression, stretching, rising magma, new mountains, collapsing Nevada, huge volcanic fields, Arizona mountains wearing away, all this stuff going on all over the neighborhood, but this one slab mostly stays in one piece. Why?

My personal hypothesis is, as the Plateau houses the Center of  the Universe, it necessarily stays in one piece.  I haven’t found anything in the literature to support this, so we will look at some other explanations.  By the way, the Center of the Universe is within a 100 mile radius from the confluence of the Green and the Colorado.  Let me know if you find it.

In the meantime we will see what the geologists have to say.  Usually they reach some consensus, except here.

If you want to explore all this on your own: Carving Grand Canyon, by Wayne Ranney and Geological Evolution of the Colorado Plateau of Western Colorado and Eastern Utah… by Robert Fillmore.

Posted in Basin and Range, Canyonlands, Colorado Plateau, Colorado River, Geology, Grand Canyon, Green River Formation, Plate Tectonics, Stories

Weird Wyoming

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Along with having the entire atmosphere pass through the state in any 24 hour period, Wyoming has some other attributes beside the wind.  I like Wyoming for its diversity and the fact it doesn’t have too many people.  The diversity also extends to the geology. Prairie in the east, Devil’s Tower and the beautiful country around there to some of the most spectacular alpine country anywhere, even if the mountains are lower than ours in Colorado.  Oh, and Yellowstone, our first National Park.

Wyoming Geology

I especially like the deserts, like the Great Divide Basin, aka the Red Desert, a depression rimmed by the Continental Divide.   Yellowstone is the largest and most dangerous volcano in the country.  There is coal, iron ore, oil and gas, uranium, and trona, to name a few.  Those resources are a double edged sword, leading to a boom and bust economy.  Ranching just soldiers along,  but it is a hard way to make a living.

A good portion of the economy comes from Greens (Coloradans, known for their green license plates).  It’s the topography that draws me.  Rivers flowing north, through mountain ranges, fed by hot springs.  A range of hills known as the gas hills, where methane comes out of the ground.  Mountain ranges running north and south as God intended, but the Snowy Range runs east-west and is the boundary between the ancient island arcs known as Colorado and the much more ancient Wyoming Craton.

The Wyoming Craton has some of the oldest rocks in North America, sharing the antiquity with the Canadian Shield.  Ages vary but are around 2.6 to 2.8 billion years old.  The oldest rocks in Colorado are around 1.7 billion years old and arrived as an island arc smashing into Wyoming, much as Indonesia and the Philippines are headed to Asia.

Wyoming has had a lot of activity down deep, shoving mountains up and sliding them around.  That pushing and shoving means areas where oil and gas get concentrated in the bends and corners, thus all the oil patch work there.  There is a lot of coal. The Union Pacific got its coal right near the tracks, and there is a tremendous amount of coal in the Powder River basin.  Coal is out of favor now, so Gillette is hurting, people leaving.

The reason Wyoming got famous is for two reasons, unruly Indians and the livestock business.  There was a lot of Indian fighting in the middle of the nineteenth century, what with the Oregon Trail crossing the region.  When the Indians were whipped, all that empty country became home to cattle and sheep.  The livestock people still hold most of the political power – they also have oil and gas leases, so they aren’t very environment friendly.  Lots of cowboy legends came out of the place.

My favorite things are the rivers running through mountain ranges.  The textbook example are the Wind and Bighorn rivers.  They got their names because early explorers didn’t realize they are the same stream bisected by the Hot Springs Mountains.  The Bighorn flows south through Thermopolis and its hot springs and roses into a beautiful narrow canyon.  The Wind River flows out of the canyon.  The river was there, the mountains came up, and the river (rivers?) stayed in the same place, cutting the canyon as the uplift occurred.

Do I need to say the Wind River is aptly named?  Years ago in Colorado Springs I met a bicyclist doing a ride across the country.  He came across Wyoming.  He looked at me and in awe said,  “The Wind”.  He rode into the wind all across the state.  Another time I was driving from Laramie to Fort Collins after dark. It was Christmas time and the ground blizzard was in full song. I saw a VW bus along the road near Tie Siding. In conditions like that, you stop.  The occupant was from Australia and said “I’ve never encountered weather like this.”  It was around zero with 50 mph wind.  The VW had quit, probably a frozen gas line, and his wife got a ride into town to get help.  Shock and awe.  I just laughed and saw he was OK.  You know about the Wyoming Wind Gauge.  It’s a length of heavy chain hanging from a post.

Jackalope,, Wyoming State Animal

There is usually a Jackalope colony nearby.

There are three books I recommend:

Rising From the Plains, John McPhee; Roadside Guide to Wyoming Geology; and Wyoming Geologic Highway Map

Posted in Coal, Geology, Green River Formation, John McPhee, Stories, Volcanos, Wyoming, Yellowstone Volcano

The Empty Quarter

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Portion of Flat Tops Wilderness

Well, its not a quarter of Colorado, but it’s big and pretty empty.  North and west of the Colorado River and south and west of the Yampa River, the only towns of any size are Rifle, Silt, Newcastle, and Glenwood Springs along the Colorado; and Meeker in the middle.  Craig and Hayden are on the  Yampa.  I don’t count Rangely on the White River west of  Meeker as a real town.  It is just a bunch of oil field junk with a few forlorn people. I recently traveled through the heart of the region.

I am a Western Slope native, so I have been over the relatively well traveled roads.  I-70 (previously highways 6&24) and SH 13 from Rifle to Craig.  As a kid, I went fishing on Rifle Creek with my parents.  The

White River

White River drains the White River Plateau and The Flattops.  Piceance Creek drains the Piceance Basin and enters the White between Meeker and Rangely.

Meeker is a pretty town in the valley of the White River.  It’s a farm and ranch town with a sad past.  The Meeker Massacre in 1879 was the end of the Utes huge reservation  lands in Western Colorado. They were shipped to Eastern Utah.  The reason was the systematic U.S. Policy of cooping the Indians up or killing them.  There are grisly details, but it was just another example of the U.S. Policy of mistreating Native Americans that continues to this day.

Maybe you have heard of Trappers Lake.  It is an enclave surrounded by the Flattops Wilderness, a huge area of timberland dotted with many small lakes.  The only access is on horseback or backpacking.  It’s wet country, catching the storms as they leave the lower country to the west.  Hunters, fishermen, and tree huggers are the only travelers.

I never backpacked there, but two friends humped there way in years ago.  They talked about the beauty,  but mostly about the rain.  One of them had one of those convoluted open foam pads with no cover.  When the water came into the tent, he was lying on a sponge in a soaked down sleeping bag.  They left early.

West of SH 13, along the Grand Hogback,

Grand Hogback Between the Colorado Plateau and the Rocky Mountains

you are on the Colorado Plateau.  Go east, and you are in the Rocky Mountains, but not the Rockies you are used to.  The hogback is a remnant of the uplift that formed the Rockies.  The equivalent on the east side are those red rock hogbacks called the Flatirons, Red Rocks, and the Garden of the Gods.

No big mountains here, just a region of high plateaus.  The reason? Volcanism in the form of lava flows.  The White River Plateau was uplifted along with the rest of the Rockies, but instead of being eroded into those jagged peaks we are used to seeing, the basalt from the lava flows formed a resistant, flat caprock.  It’s not rugged mountains, but it has a beauty all it’s own.

Flat Tops Trail

The is a scenic byway between Meeker and Yampa I took for the first time,  At first, it is in the White River valley, then climbs up on the plateau and heads on east to Yampa.  The view to the south is where the Flattops drop down to the river.  It’s not a gentle slope.  The basalt caprock is underlain by the soft White River Formation.  The steep slope is subject to landslides, leaving large open, green slopes surrounded by timber.  It’s great summer range country for sheep and cattle.  It is also some of the prettiest country in our state.  I think I met two pickups on the road east of Buford, where the road turns off to Trappers Lake.  It’s gravel much of the way, but good gravel.

West of SH 13, on the edge of the Colorado Plateau, is the huge Piceance Basin.  It is a Structural basin next door to the Uinta Basin, mostly in Utah.  The basins are separated by the Douglas Arch, crossed by Douglas Pass, country where I spent a lot of time in my youth.  The arch is a western extension of the Laramide Orogeny, the mountain building period that formed the Rocky Mountains.  The edges of mountain ranges usually have foreland basins, areas of subsidence.   I am sitting over the Denver Basin.  The Piceance is the equivalent west of the mountains.  As the mountains rose, the fringes sank, creating huge synclines filled with the erosion products of the mountains.    The basins formed huge inland lakes which filled with sediment that became the Green River Formation, famous for its fossils and oil shale.

The Greater Piceance Basin

Because of all that rising and sinking, pockets form, trapping reservoirs of gas and oil.  The Piceance is one of the most productive natural gas fields in the country.  Rangely’s oil is also from the Piceance.  I drove the road running along Piceance Creek, which drains the basin to the west.  The area is all about natural gas, with some ranching along the creek.  There is a gas plant every few miles, and lots of truck traffic.  The basin used to be the home of a huge migratory deer herd, the deer summering in the Flattops and wintering in the basin.  The herd is still there, but all the drilling has greatly reduced the numbers.  Lots of elk there as well, their numbers increasing somewhat, probably due to less competition from deer.

The area is known as the Roan Plateau, which drops off to the Book Cliffs, an escarpment runnng from Palisade, CO to well past Greenriver UT.  It feels like home country to me, with memories of deer hunting in the Douglas pass area.  The scenery isn’t as dramatic as the red rock country to the south, but has its own beauty.  Plus, it isn’t as cluttered up with people.

Piceance, Uinta, Roan Plateau, Book Cliffs, all names for roughly the same country.  My list now includes going up into the basin proper, known mostly by Ute Indians, ranchers, oil field people, geologists, and aging wanderers.

Posted in Bookcliffs, Colorado Mountains, Colorado Plateau, Geology, Green River Formation, Road Trips, Stories, Western Colorado

rat in cage two bottles

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The World Famous Green River Formation, for oil shale, not beauty

The World Famous Green River Formation, for oil shale, not beauty

About fifty million years ago the Grand Canyon and the Colorado River did not exist.  The area was surrounded by the Wind River Mountains, the Uintah Mountains, the San Juans, the Uncompahgre Plateau, and the newly formed Rocky Mountains.  This huge area had no outlet to the sea.  The climate was similar to our current Gulf Coast, warm and moist.  During the six million years we are exploring, things changed.  Lakes formed and receded, land rose and subsided, and through all this the surrounding highlands were sending their sediment into the lakes.   

The Green River Formation is the result of all the sedimentation.  It is up to ten kilometers in depth, thinner at the margins.  At first the lakes were fresh water, but later became saline, leaving large deposits of carbonate rocks.  The trona deposits at Green River, Wyoming are some of the richest in the world.  The margins are sandstone and conglomerate interlaced with the fine silt that filled most of the basin.  The formation is rich in the fossils of the abundant life in the lakes.  They are world famous for their variety and abundance.   

There was an anoxic layer at the bottom that preserved the organisms settling there.  The lakes were abundant in blue-green algae.  The remains of the algae are the source of the oil shale deposits the region is known for.  The oil shale is there in millions of barrels, but it is expensive to extract the petroleum from the rock.  It may never be commercially viable, but the formation has been extensively studied as a result.  

Green River Formation Map

Green River Formation Map

Standing in my home town of Fruita looking north, the white cliffs behind the Book Cliffs are the Green River Formation.  The Roan Plateau is huge, but does not attract visitors like the red rock country to the south.  A huge exposure is the highlands west of I-70 from Rifle to DeBeque Canyon. 

My interest is from visiting ranchers and hunting in the Douglas Pass area in my youth.  Most of our visits were to ranches in the Green River Formation.  The elevations varied greatly.  The ranches were along West Salt Creek, but there were back country roads that went from sagebrush desert to piñon-juniper to oak brush shaly hillsides with sandstone rims to high country timber with world class mud.  In fact, the mud is world class everywhere in the region. 

Back before four wheel drive became common, there was a pile of rocks at the bottom of every big hill.  Load them in the back of your pickup, go where you planned, and unload them on the way home.  There is a network of canyons with side canyons branching off.  All of it is fine deer habitat.  My favorite places were at the head of a canyon with the wind in my face and a view of the LaSal Mountains and the Uncompahgre Plateau in the distance.  Flat, wooded country gives me the creeps. 

Access to a lot of the country is difficult.  Most of the land is BLM land, but the early ranchers homesteaded the choice land that had water.  The private land meant locked gates.  We knew some of the ranchers, family friends.  Hunting season was a big deal.  There were maybe a dozen or more people, hunting during the day and drinking and playing poker at night.  The big ranch house had a big kitchen with a wood burning stove along with the stove in the big main room.  There was a light plant in the shed next to the house.  It looked like no generator you see these days.  There were also lots of Coleman lanterns when the light plant failed.  Good times and lots of venison.  The unheated bunkhouse was upstairs. 

Douglas pass was up the main road, gravel in those days.  It isn’t that high by Colorado standards, but made up for it with the switchbacks up the head of the canyon to the summit up through that shale.  When the shale is wet, it moves.  The road trapped the runoff, wetting the soft shale, and most every spring one or more places slid.  The mountainside now is braided with old road cuts.  It wasn’t much of a main road in the 1950’s, but now there is so much oil and gas development that the road is a paved state highway that the highway department spends money on. 

The road crosses the desert above the Highline irrigation canal before it goes into the canyon.  It is on the Mancos shale, responsible for all that flat desert in Colorado and Utah that turns to grease when it is wet.  There was one hill the road went over then descended into the wash on the north side.  That meant the road was on a north facing slope for a distance.  That hill was named Coyote, because it could bite and gnaw on you if it was wet.  A bit farther north was a ten or twelve foot high rock on the side of the road, all by itself.  

The county employee maintaining the road in those days had his grader blade scrape on that rock every time he bladed the road.  It would leave a bump, so he would have to drag dirt over to level things out.  One day he got fed up and dug that rock up and moved it off the road.  It was probably a two day project, but he never had to fight that damn rock again. 

After I could drive, I ran around that desert quite a bit.  I learned how to drive a two wheel drive pickup in that greasy stuff from my father.  He was the telephone man in Fruita, responsible for maintaining the toll line as far as Cisco, Utah.  That meant navigating two ruts through the cheat grass and sagebrush.  He could put a two wheel drive pickup into places that were a challenge for a Jeep.  Rocks in the back, chains if needed, put it in second gear and putt along.  He seldom used the granny gear or used the gas pedal.  Those old Chevy sixes would just lug their way along.   

I am as guilty as any back country explorer for spending most of my time in the Rocky Mountains or the Utah red rock country, but the Mancos Shale and the Green River formation are calling me.  I just need to see if my tire chains are in good shape.  I think I will go over Douglas Pass, loop around and look the Piceance Basin over. From Rifle I will go down to Plateau Creek (my father and grandfather said platoo crick) and up to Collbran to look at the big slide.

Posted in Colorado Mountains, Colorado Plateau, Colorado River, Federal Land, Geology, Green River, Green River Formation, Landslides, Oil Shale, Pipelines, Stories, Uncompahgre Uplift, Utah, Western Colorado