Journeys in the Back of Beyond: Simply Driving to the Bottom of the Grand Canyon (!?)

Running a geology field studies course is nothing if not stressful. Right on the heels of the most intense storm I've experienced on one of these trips, it was morning and we were on the road to the next thing. A simple thing really, just driving down to the bottom of the Grand Canyon. But I had no way of knowing it would happen, given the storms of the previous night. Had the storm affected the road into the canyon?

 
The Grand Canyon is one of the great spectacles of the Earth. Millions of people every year stand on the edge of the abyss and peer in, taking in the vivid colors and hidden depths. Tens of thousands venture down some of the few trails that reach into the incredible gorge, and several thousand raft the river. But how many drive the canyon? Did you even know you could?
And no, I'm not talking about visiting the canyon "Thelma and Louise" style...

For more than two hundred river miles, no road crosses the Grand Canyon (plus another hundred miles along the shores of Lake Mead). Navajo Bridge near Lee's Ferry is at one end, and Pat Tilman Bridge near Hoover Dam is at the other. In between in the depths of Grand Canyon there is a single road that reaches the river. It's called Diamond Creek Road, and it starts on Hualapai Nation land at Peach Springs, Arizona. It's a marvelous adventure.

The "diamond" that gives the road its name: Diamond Peak

Without even considering the philosophical objections to building roads through the wilderness world of the Grand Canyon (objections I completely agree with), there are staggering engineering barriers. There are a series of formations, including the Redwall Limestone and the Coconino Sandstone that form sheer cliffs. The locations of trails in the Grand Canyon are controlled almost entirely by the few locations where they can surmount the cliffs of these two layers.

At Diamond Creek, the Hurricane Fault has offset the formations in just such a way that the cliffs can be avoided entirely. For the entire twenty mile length of the road, there is nary a cliff to worry about, as the road follows the bottoms of desert arroyos and washes. The biggest worry is flash floods and mudflows, which can easily shut down the road in July and August during the monsoons (and badly inconvenience river rafters who plan to take out at Diamond Creek). Unfortunately, our storm had all the hallmarks of an intense monsoon storm, and for all we knew, the road would be closed, and the whole endeavor moot. We were running late anyway, and I couldn't know the status of the road until we reached the Peach Springs office of the Game and Fish Service of the Hualapai Nation. We got there, and the sign on the door told me the worst...

All my plans dashed. But what can you do but barge your way into the office and see if the road was really closed? And it turned out that their closure was cautionary, the sign left from earlier in the day when no one had checked the road conditions. The road was okay, and I was given the permit to take our group into the canyon (the form interestingly was a permit to trespass on Hualapai land). It was the only permit given that day, and we would have the Grand Canyon to ourselves! We started down the gravel road, the Colorado River twenty miles away.

One can certainly debate the idea that it's "cheating" to drive to the bottom of the canyon, and there is a certain validity that scenery that hasn't been "earned" by completing a stiff hike might end up being less appreciated. But many people can't handle the very strenuous hiking and many simply don't have the time. Driving down into the canyon is a unique opportunity to study the oldest rocks of the canyon, the ones that are the very hardest to access in any other situation.

Diamond Creek cuts through to the Granite Gorge Metamorphic Suite, which is the oldest group of rocks found in the American Southwest, dating to as early as 1.8 billion years ago. At roadside there are marvelous exposures of schist, gneiss, and pegmatite granite with bright shiny crystals of muscovite mica and quartz.

Outcrops of schist intruded by pink pegmatite granite

A bit farther up the canyon one can see the layers of the Tonto Group, a series of three formations called the Tapeats Sandstone, the Bright Angel Shale, and the Muav Limestone. The three layers formed as the Pacific Ocean transgressed and covered much of the western North American continent in Cambrian time, just over 500 million years ago. The Tapeats Sandstone sits atop the rocks of the Granite Gorge Metamorphic Suite.

The Great Unconformity: the vertically oriented rocks in the lower half of the photo are the ancient metamorphic schist and gneiss. Above the metamorphic rocks are horizontal layers of the Tonto Group.

That last sentence needs a bit more explanation. The boundary between the Tapeats and the Granite Gorge rocks is a profound unconformity representing a gap of more than a billion years. This unconformity is actually called the "Great Unconformity", and is an erosional surface that was witness to not one, but two major mountain-building events. The metamorphic rocks were once the core of a vast mountain range that formed 1.7 billion years ago when the North American continent collided with a set of two exotic terranes, the Yavapai block and the Mazatzal block. Imagine an island the size of California or New Zealand grinding into the edge of a continent along a subduction zone and you will get the picture. This massive mountain range eroded to a flat low-relief surface over the next few hundred million years.

The Great Unconformity up close. Dark brown conglomerate of the Tonto Group rests unconformably atop the ancient metamorphic rocks.

Later on, about a billion years ago, the continent stretched and broke apart, forming a series of fault-block mountain ranges that reached heights similar to the mountains in and around Death Valley National Park today. The rocks of these mountains are exposed in the easternmost part of the Grand Canyon, but they too were eventually eroded down to a low-relief surface as well, although small  ridges a few hundred feet high persisted. Along the lower reaches of Diamond Creek Road, you can lay your hand on a boundary between two rock sequences with a gap of more than a billion years between them. The unconformity can be seen in the photo above where a conglomerate rests on contorted metamorphic rocks in the bit of shadowed ledge. The "Diamond" of Diamond Creek is the uniquely shaped peak on the left side of the photograph. It is actually a sliver of rock caught between two branches of the Hurricane fault system.

Another layer that is prominently exposed along Diamond Creek Road is the Devonian-aged Temple Butte Limestone. Most park visitors never see it because in the eastern section of Grand Canyon National Park the Temple Butte is a discontinuous thin layer that is pretty well invisible from the rim. In western Grand Canyon it is more than 700 feet thick. It formed as a tidal estuary and tidal flats along the edge of the continent about 385 million years ago.

Temple Butte cliffs in Diamond Creek

We reached the end of the road where Diamond Creek flows into the Colorado River, the watercourse responsible for carving the Grand Canyon. It was a moment for the students to cavort in the river for a few minutes, and to wonder at the work the river has done. This spot is where many of those who've rafted the river through the Grand Canyon take out, a usually raucous process, but no one was about on this particular day.

The most "mysterious" aspect of Diamond Creek and Peach Springs Canyon is that the tributary canyons to this creek follow illogical pathways, and are actually older than the Grand Canyon itself! It's an odd problem. Along the upper reaches of Peach Springs Canyon, there are a series of Paleocene to Miocene-aged rocks clinging to the canyon walls. They once filled the canyon, meaning the canyon was carved prior to sixty million years ago, and the rivers that carved it flowed northeast, opposite of the Colorado River today. Apparently the land subsided so that the canyons were filled with sediment, and then they were exhumed when the modern Grand Canyon was carved, most likely within the last four or five million years. There has been more than one Grand Canyon carved through the Colorado Plateau!

Peach Springs Canyon  (red) and the odd channels (blue) that were carved millions of years prior to the Grand Canyon itself (they were buried and exhumed when the modern canyon was carved).

Near the bottom of the road we happened upon a Bighorn Sheep. They were once more common and figured prominently in the Ancestral Pueblo petroglyphs found throughout the region. 

Diamond Creek is a fascinating excursion. It is entirely on Hualapai lands, and they charge a fee of around $17 per person for permission to drive the road. I never mind paying the fee, because the tribe doesn't have many sources of income or all that many jobs on the reservation. The town of Peach Springs where the road starts has a very nice motel and restaurant (and not much else), and if you are a train lover, you'll be able to listen to them all night long. The rails are amongst the busiest you'll ever see. The town is on one of the last remaining stretches of the original Route 66.

Our crew was ready to get to camp, so we drove an hour or so to my brother's cabin where we would spend the next three nights.

Wait a minute. Showers, kitchen, hot tub? You call this roughing it?

Journeys in the Back of Beyond: Starting Off With a Bang

 

The Granite Mountains adjacent to the Mojave National Preserve

Actually it was a great many bangs. I shall explain...

Let's start with some basic statements. It's the Mojave Desert. It's almost summer. It doesn't rain in deserts, sort of by definition. I plan these excursions to avoid the monsoons of the Desert Southwest. And as the host at our first camp told us, "average June rainfall is 0.01 inches". We'll get back to this interesting meteorological situation shortly...

The first day of our trip was a traveling day, somewhere around 400 miles to get us out of the Central Valley and well into the Mojave Desert so we could reach the Grand Canyon the following day. My marvelous and courageous crew consisted of 17 students and several valued and faithful volunteers who have been making these trips possible for many years. We had a wonderfully diverse group, with some in their late teens, and others in their 60s, 70s, and one incredible traveler well into her 80s. 

All adventures devolve quickly into several basic questions: where is the nearest restroom? Where is the next mini-mart/gas station? How far do we have to camp? Sometimes, to my delight, there is a question about some geological feature visible in the distance: Is that a volcano out there? What's that weird white rock? Our expensive walkie-talkies ($9 each on Amazon) kept us in touch.

We made good time, and even had time to stop and have a look at the vast open pit mine at Boron (source of around half of the world's production of borax minerals). We pulled up to camp about 5 pm and started setting up.

The setting was dramatic. We were tucked in a small draw at the base of the Granite Mountains, which by incredible coincidence are composed almost entirely of granite. This granitic rock has the same origin as the famous granite batholiths of the Sierra Nevada, having been intruded into the continental crust as a result of subduction along the coast of western North America. The sinking slab of oceanic crust heated up and portions of it melted to form the granite magma that forced its way upwards through the crust where it eventually cooled. The subsequent history of the rock was different, however. Where the Sierra Nevada rose as a single massive block of crust sloping to the west, the Mojave twisted and deformed into a series of individual mountain ranges of more moderate elevation.

I guess I should have known what was coming. In my trained scientific experience, if there is a storm anywhere in sight, it will find a way to hit us. Despite the summer temperatures, skies were overcast, and there was a lot of energy in the clouds around us and rain was falling on the distant horizon. Camp was set up and we were preparing our dinner for the night when our phones simultaneously chirped, giving us a flash-flood warning. It was no spurious warning, either. Moments later, the sky opened up with the most intense hailstorm/rainstorm we've ever experienced in 40 years of field studies.

In mere moments the ground was covered with more than an inch of hail, some hailstones as large as quarters (the hood of my Subaru has dozens of small dings on it now). Every small gully and watercourse was filled with flowing water, including our entrance road. And the lightning was constant and terrifying (I didn't grow up in the Midwest, so these intense kinds of thunderstorms are new to me).

What had been dry sere desert moments previous was now coated in a covering of ice. There was enough hail left on the ground the next morning to use in my ice chest. It was a stunning storm.

The next morning as we left for Arizona, we realized we were lucky to be able to leave at all. Our access road had transformed into a river overnight, complete with braided stream channels, and some mud puddles remained that we carefully forced our way through.

Rivers had flowed over Kelbaker Road, but thankfully had not washed out the pavement.

Some nearby roads had been washed out and were closed to traffic, but we were able to reach the main highway and continue our journey east.

How did my students fare in such an incredible storm? 

I should backtrack a bit and explain what happened a few weeks earlier. In past trips we've always stayed at Black Canyon Campground in the Mojave National Preserve. It's a nice spot, and even has a shade structure that could have served as shelter from the downpour when it came. But I was poring over the maps and noticed the Sweeney Granite Mountains Desert Research Center. I remembered touring the place several decades ago, so I looked it up and discovered they had a cabin for use by students and researchers on the north slope of the Granite Mountains. On a whim I asked if they could accommodate our crew, and they were able to do so. 

During the worst of the storm, we were lounging in a nice dining/study area in a cabin!

The Granite Mountains Preserve is administered by the UC System, and covers around 9,000 acres of granite mountain slopes covered by pinon-juniper forests (and an uncomfortable amount of jumping cholla). They do research on all aspects of the desert/mountain ecosystems. There are several different kinds of accommodations for researchers, including the Norris Cabin where we stayed (below). It is a wonderful setting for field work in the desert!

And thus the first 24 hours of our two-week trip was done. The crew had been tested against the single worst storm our program had ever experienced and came out ready for more. Our next destination was the bottom of the Grand Canyon!

Journeys in the Back of Beyond: Adventures on the Colorado Plateau

 

Devils Garden in Arches National Park

What is an adventure anymore? 

I ask my students to describe the meaning in one of my offbeat assignments in my geology courses and I get all kinds of answers. Many will describe a experience from our local educational camp in the Sierra Foothills, or an excursion they took to a local river or lake. Many of them have almost never left the city limits, and camping in the Sierra to them is terra incognita, far beyond their experience or expectation. 

I've always known I've had a blessed life in many ways, and what has made it especially rich is the privilege of leading my students on true adventures way out there in America's Back of Beyond, the Colorado Plateau and the Basin and Range country. I've just returned home from one of those journeys.

In Zion National Park

"Back of Beyond" is informally defined by Merriam-Webster as "a place that is very far from other places and people: a remote place". There are literary connections in the writings of Edward Abbey and C.J. Box, and a 1954 documentary from Australia. It is also the name of one of the finest bookstores in Utah. Outside of Alaska, some of the wildest and remote country in the United States is indeed the Colorado Plateau and the Great Basin, and to me it is some of the finest scenery in the world, and its geological story is fascinating. And...the land is endangered.

I'd like you to experience this country, if only through narrative and photography. I hope you will join me over these next few weeks as I describe our experience in a series of blog posts, and perhaps understand why we need to take action to protect the heritage of these fragile lands.

Mesa Arch in Canyonlands National Park

As usual, my ambitions often exceed my time allocation, so forgive me if delays occur in new postings!