Into the Great Unknown: Heat...and All Things Beautiful

It was our last full day on the Colorado River through the Grand Canyon, the Great Unknown as John Wesley Powell called it in 1869. One full day, and one more night on the life-giving stream of water through one of the spectacular canyons on Earth. We had eighteen miles to go, from our camp at Mile 202 to 220 Mile Camp (it was clear that the geographers were running out of names for the features in the canyon; it's that big).

It was a day full of the best things the canyon could offer. But it was also hot. Blazing oven hot. Merciless sun beating down hot. In other words, a normal summer day in the Inner Canyon. The thing is, we had already experienced a few hot days on the trip, but not quite the kind of 115 degree days that we were warned about in the training materials. I don't actually know how hot it got, but in my memory, it was the hottest day of the trip.

They said a few things in the training videos for rafting the river. To drink before you get thirsty. To drink a gallon a day. To always wear a hat. Seek out shade when possible, and don't hike between 10 and 4. They said it takes a human body about two weeks to acclimate to extreme hot temperatures, meaning a river trip was not long enough to do so.

We were seeing all kinds of adaptations to the heat as we explored the area around our camp during the relatively cool morning hours. We had dropped nearly 2,000 feet during our two weeks on the river, and the desert vegetation was characteristic of the Lower Sonoran Life Zone (or whatever the biologists are calling it these days). Cacti had been rare in the upper reaches of the river, but now they were common.

There were a few shrubs with their characteristic waxy leaves taking advantage of the recent storms by putting out a few flowers.

Best of all were the ocotillos that we had been seeing for the last two or three days. They too had taken advantage of the recent storms, and had put out thin leaves along their green branches (most of their food production happens in the branches rather than the leaves). There were none of the beautiful  red flowers (we'd need to be here in May for that).

We took advantage of the relative cool of the morning to search out some pictographs that were said to be up in 202 Mile Canyon. It took a while (which is why I had given up and photographed the plants instead), but eventually we found them. It was a small measure of the rate of geologic change that some of the blocks of rocks containing the rock paintings had tumbled down from the ledge.

Once the sun reached our boats, we set off down the river. We continued to see remnants of the lava flows that had once produced high dams, and which had continued downstream for many tens of miles (above).

We also saw another gigantic landslide that had involved the entire canyon wall (above). Lava flows aren't the only things that have produced dams on the river. As noted in an earlier post, landslides have altered the course of the river a number of times.

We saw more evidence of human occupation in the canyon. We discovered roasting pits in several of the debris fans at the mouths of some of the tributary streams. Along with the cracked and shattered rocks we found bit and pieces of pottery.

A short hot hike up Indian Canyon offered a fine view up the river. But it was hot and there was no shade. I shiver to thick how quickly I would have been in trouble here had I not been carrying a quart of water at all times. I was drinking at least a gallon and a half of water on days like this, and when it got too uncomfortable, I could splash in the river water to cool off. Despite being 200+ miles downstream from Glen Canyon Dam, the water was still in the mid-to-upper fifty degree range.

The scenery continued on a grand scale, with high cliffs at every turn. We saw another bighorn along the riverbank. It was as if the river was giving us reminders of why the canyon was precious. And that was the way I was feeling. This was the last full day, and while I was wanting to see the people I was missing in the outside world, I was also feeling like I wanted to hold onto these incredible experiences that I felt were enriching and transforming my life.

We crossed the Hurricane Fault again, and the ancient Vishnu Schist was exposed at river level once more.

 In the intense sunshine, the polished surfaces of mica, quartz and feldspar reflected brightly.

 It's amazing what the silt-filled water can accomplish!

 As we searched for (unsuccessfully) for a shady lunch stop, we encountered an unusual looking ledge of Tapeats Sandstone on the left bank.

The top of the ledge had been scoured and eroded by river currents, and it looked recent, yet the bench was 15 or 20 feet high. It looked extremely fresh.

 At the lower end, there was a strange orange-colored edifice called Pumpkin Spring. It was a warm spring deposit that was redepositing travertine that had been dissolved from the overlying limestone formations. The heat probably came from nearby active fault zones. The water was green and uninviting. The river guide suggested not drinking it because of high concentrations of arsenic (is that a poison or something?).

 We set up a canopy and crowded underneath it to eat lunch. There was a hot breeze blowing so the shade barely helped. Unfortunately the wind was trying to destroy the umbrellas that most of the boats had, so there was really no place to retreat from the sun. For pretty much the first time voluntarily, I spent most of the time soaking in the river as long as I could stand it (cold!), then getting out and warming up until I was dry and hot, and then getting back in the river!

Despite the heat, we wanted to check out the unusual terrace in the Tapeats Sandstone that we had just floated by. We grabbed some water and headed back up the canyon. The edge was pockmarked with huge potholes, many of which had carved right through the rock, forming little tunnels and caves. Many of the potholes still had the pebbles and cobbles that had carved them.

It turns out the terrace has been flooded by river water in historic time during the big spring floods, but only rarely since the floodgates of Glen Canyon Dam shut in 1963. The dam is still altering the river, even 200 miles downstream.

 We made one more stop that afternoon, at Three Springs Canyon. Like so many tributaries, it had a small stream of clear water that we could use for drinking. Some of the crew pumped the water filters while others hauled the five-gallon buckets down the trail to the boats.

 Yours truly found he could make a human dam across the trickling creek and have a nice bath.

It was the hottest part of a very hot day, and a hot breeze was blowing up-canyon. No one felt like rowing against the wind, not in the hot sun without the umbrellas. We holed up in the shade behind a ledge at Three Springs Canyon for quite awhile, letting the afternoon shadows extend across the canyon a bit.

 We arrived at our site for the night at 220 Mile Camp. As if to make some kind of point so late in our trip, it was one of the most beautiful camps of the trip. There was an island of Vishnu Schist in the river decorated with a few wispy tamarisk saplings. Our camp was in the shade (relief!), but the sun was shining brilliantly on the cliffs across the way, reflecting on the river.

The view upstream was gorgeous as well. At this late point in the day, no one else was on the river; the feeling of isolated wilderness was complete. It was strange to think that only six miles away a road reached river level, and that we would be driving out of the canyon in the morning.

We drank the last of the beers and the sodas, ate most of the remaining food, and sat in the warm air watching the sunlight drain away from the cliffs as night fell. After a while, a cool breeze wafted off the surface of the water.

The moon was a touch higher in the sky than the previous evening (it always happens that way), but it soon dipped below the cliffs. It was the 11th of August and the Perseids Meteor Shower was scheduled to debut in the night sky. It did not disappoint; as we talked and sang and played the guitar, I counted maybe a hundred shooting stars, some of them blazing a trail all the way across the sky. I had been turning in early on many nights of the trip, but on this night I was still awake staring at the show in the sky until well past midnight. I'll not forget it any time soon. I didn't want the night to end, and yet I did.

Tomorrow we would be back into civilization, and I would be starting the journey home...

What's Missing From This Picture? Only a billion years or so...

Geology is good for perspective. The bookends of this particular day: the very very long hour spent trying to restart a dead car in a remote canyon, and a billion years in one hand. I'm on the road researching a field seminar for the AAPG in Arizona and Nevada, and I saw some incredible things.

1.7 billion years ago, fragments of continental crust were colliding to form the core of a new North American continent. Those mountains climbed to the sky, rivaling the Himalaya or the Andes in their grandeur. The time was so ancient that not a bit of life existed on the mountain flanks. The only lifeforms at all were single-celled organisms in the oceans.

The forces pushing the mountains upwards ended, and the ice and rain tore away the flanks. The gigantic peaks eroded to hills, and in hundreds of millions of years, the hills eroded to nearly flat plains. They were gone, but the rocks that formed the roots of those mountains remained. Around 530 million years ago, the continent had begun to break up, and the edges subsided slowly while a shallow sea advanced. The beach sands swirled back and forth across the roots of the ancient mountains.

An unconformity is a buried erosional surface. Sometimes the time missing might be a few hundred thousand or a few million years. The unconformity in the Grand Canyon is profound, representing a gap of a one thousand million years. Get to the right place, and you can place your hand across 1,000,000,000 revolutions around the sun: nearly a quarter of the age of the Earth.

The problem with the Great Unconformity, as the early geologists called it, is that it is mainly exposed in the bottom of the Grand Canyon. There are only a few ways to see it and touch it: you can float down the Colorado River in a raft, or you can walk down the long difficult trails from the rim of the canyon. Or, as it turns out, you can drive.

I left Las Vegas this morning and traveled up Lake Mead Boulevard. The growth of the town has slowed with the depression, but over the last twenty years I've watched the urbanization of the valley wash up the slopes of Frenchman Mountain on the eastern edge of town like a tsunami. Fortunately, the wave stopped at the boundary of the city limits and the federal lands around Lake Mead. It turns out that the rocks making up the Great Unconformity are exposed no more than a mile from the residential neighborhoods of Sin City. The sand layers of the Tapeats Sandstone cover the weathered granite and schist of the 1.7 billion year old basement complex.

The geologists at the University of Nevada, Las Vegas knew of the treasure in their backyard. Years ago they set up a trail and some very nice interpretive exhibits. I regret to say that vandals and garbage dumpers destroyed the exhibits in a short time, but you can still see the rocks.

If the exposure lacks anything, it is grandeur. The oldest rocks of the Grand Canyon are at the bottom of one of the deepest and longest gorges in the world, and there is much to be said for seeing the rocks in their full perspective, underneath a mile of subsequent sedimentary layers. When time or health is short, hiking or rafting is not feasible. But I was on a mission today, to see the only place in all of the Grand Canyon where one can drive to the Great Unconformity. It is well-known to rafters as it is the take-out point for the river voyagers. It's called Diamond Creek, and Peach Springs Canyon. The road starts at the administrative headquarters of the Hualapai Nation in Peach Springs, and winds 19 miles and 3,500 feet down to the Colorado.

Anyone who has seen the Grand Canyon, either in pictures or in person, has to wonder how any road could intrude into such rugged terrain. There are so many cliff-forming layers that a road seems next to impossible (which it is, given that only one exists). But Grand Canyon is also crossed by faults and folds, and the disruption of the cliff-forming layers is what makes roads and trails possible. The road starts innocently enough, dipping into rolling terrain composed of Mio-Pliocene sediments that have huge significance in understanding how the Grand Canyon was carved. We actually follow canyons that originated at the end of the age of the dinosaurs (the Cretaceous Period) and were subsequently filled, and then exhumed in the last hiccup of geological time.

Heading deeper into the canyon, we see some evidence of deformation; in the picture below, we can see a gentle monocline crossing the picture where the layers step down in elevation without splitting. A major fault zone, the Hurricane fault, crosses the canyon in front of the fold. The road turns and follows the fault zone.

The gorge becomes deeper and deeper, and we pass into older and older layers. The Mississippian Redwall limestone forms the highest cliffs, and the lower cliffs are dominated by the Devonian Temple Butte limestone and Cambrian Muav limestone. The gentler slopes cover exposures of the Cambrian Bright Angel shale. The rocks on the left side of the canyon sit around a thousand feet lower than the rocks on the right due to displacement along the Hurricane fault.

The cliffs grow higher and higher, and we finally reach the base of the Paleozoic rocks with exposures of the Tapeats sandstone, the same layer seen at Frenchman Mountain in Las Vegas. The Tapeats can be seen in the first picture of this post, forming the prominent layers at the lower left. The orange-brown rocks at the base of the cliff are the 1.7 billion year old granite and schist.

It would take only a moment's walk to lay one's hand on the unconformity, but we also wanted to see the Colorado River. We were nearly 16 miles into the canyon, with only three to go. We got into the car, turned the key....and nothing. Not a click, not a warning light, nothing. 16 miles into the depths of the Earth, and we had a dead car.

So we had the longest hour I've ever felt (aside from the births of my children), trying anything and everything to get the car going again. A construction crew stopped by, five guys in one truck, and we did the engine worship thing where all six of us stood around the open hood and jiggled connections. A river runner came up the road with his boat trailer. He had room, so Mrs. Geotripper jumped in to go arrange for a tow truck. River runners like this guy drive this road all the time, so the Missus had a regular Mr. Toad's Wild Ride up the bumpy road. Meanwhile, I stayed with the car, pretty much preparing to camp out for the night. The ranger for the Hualapai tribe showed up, and we did some more jiggling of engine connections, and he helped me get the transmission unstuck, but we still weren't getting anything when I turned the key. In final desperation, we tried the obvious, and pulled out the jumper cables. They worked.

I zoomed up the road, picked up Mrs. Geotripper, and sped on to Williams without turning the car off once. Thus, our unexpected night in a motel, and a delay, looking for a saturday mechanic before we head on to Grand Canyon tomorrow. And internet access! We'll see what surprises tomorrow holds for us.

By the way, the ocotillos were blooming in the lower canyon...enjoy!

NOTE: Tourism is almost the sole source of income for the Hualapai tribe. You need to pay an exploration fee of $25/person at the Hualapai Motel in Peach Springs. Looking at the town of Peach Springs, I was glad to give them some support.

Dispatches from the Road: An Octet of Ocotillo (and other Desert Denizens).

Traveling from here to there; sought a way to Tuscon without having to go through Phoenix and found Highway 85 to Interstate 8, a route that took us right through one of our nation's youngest national monuments, Sonoran Desert National Monument.

The park, administered by the Bureau of Land Management, has not been developed to any degree, and a large portion is designated wilderness. There is a nicely situated picnic stop on Interstate 8 a few miles east of Gila Bend, and we stopped for a look.

Ocotillo is one of the characteristic plants of the Sonoran Desert (sometimes called the "Low Desert"). In spring it comes alive with beautiful red flowers, but in summer and fall it simply exists. The photosynthesis occurs mostly in the branches rather than in leaves. The swirling chaotic patterns of the stalks is irresistible to photographers (and also me).

The other more famous desert plant is the Saguaro cactus. They are not in thick forests along the highway the way they are in nearby Saguaro National Park, but their distinctive shapes seem to be on every ridge.

The monument preserves three mountain ranges. It is amazing how untouched they look, given their proximity midway between Phoenix and Tucson.

 The sun was getting low, and we still had a few miles to go.

 A long day, but a beautiful finish!

Springtime in the California Desert: Miscellany of Life at Joshua Tree

Wrapping up a week of posts on Joshua Tree National Park, I am offering up a miscellany of life at the unique park in Southern California. A visit in the middle of May is a bit past the height of spring bloom, but there were a few flowers left to enjoy, no doubt assisted by the cool spring. It certainly didn't feel like summer out there.

One of the most dramatic flowers we saw was the ocotillo, a Colorado Desert species that lives in the lower elevations of the park. The ocotillos near Cottonwood Springs were bright with color.

One of the oddest corners of the park is the Cholla Garden at the western end of the Pinto Basin. Chollas are one of the most viciously defended plants one will ever come across. The thorns of the plant are hooked in such a way that if you brush against it, the branch will break off and stick to your skin, by the painful thorns. When you try to brush it off, the thorns stick to your hand. A comb is a vital piece of hiking equipment when hiking in cholla country.

The tendency to break off, besides leading to the "jumping" legend, is also an efficient way of propagating the species. The broken branches can sprout when they get dropped off at a new location.

In most places of the lower desert of Joshua Tree the chollas are widely dispersed, but at Cholla Garden, the chollas are growing in a nearly pure stand, probably due to perfect soil conditions.

Despite the nasty reputation, the Jumping Cholla has a beautiful flower, as can be seen below.

There were a lot of diminutive flowers to be found across the desert, one of which I didn't have any resources to identify. Any help out there?

No problem identifying this one, though. The beavertail cactus is found all over, and the blooms are distinctive...

The rich vegetation was bringing out all manner of insects and birds and reptiles. At the south entrance of the park, I caught one I've never noticed before. It turns out to be a gnatcatcher, perhaps the Blacktailed or California species.

The presence of flowers meant rich time for the hummingbirds, not a species I usually associate with the desert. I saw this one near the Barker Dam trailhead.

There are the usual reptiles. This lizard was well-camouflaged at the base of a fan palm at Cottonwood Springs. I'm assuming a Western Fence Lizard, but will appreciate corrections.

Finally, a mystery beast from the desert. I saw this...something or another...walking across the desert in the Pinto Basin. I thought some kind of wasp from the size, but I haven't a clue what it really is or what that...thing...is on its back. Anyone want to pitch in here?