Saturday, July 7, 2018

Home From Back of Beyond: Images of a Harsh Country, Part Three

This first photo may recall the disasters unfolding in the American West and Hawai'i with out-of-control wildfires and volcanic eruptions, but in this case it is no disaster. It is was the sunset on the tenth day of our recent exploration of the Colorado Plateau. We had finished our explorations of Arches and Canyonlands National Park and were headed west, towards home. It's funny, the emotions that can arise on a long journey. It felt like we were nearing the end of the trip yet we still had five days and four nights to go, and there were still four national parks on the itinerary. I've put together two previous posts of my favorite shots from the trip, and this is the third and final chapter.
We had been out for a long time, so we gave the students half a day of free time in Moab, Utah to do laundry, shower, and peruse the rock shops. But first we had one other major archaeological stop to make. The sandstone walls of the Colorado River gorge downstream of Moab contain some fascinating petroglyphs. They are cleverly hidden behind a big highway sign that says "Indian Writings".
Having signs pointing to fragile petroglyphs along a busy highway might not seem to be a good preservation strategy, but in this the highway construction itself provided the protection. There was very little space along the river for road construction, so the crews removed many tons of fallen debris to make room, the same debris the original artists stood on to chip out their art. Many of the petroglyphs are now inaccessible, fifteen or twenty feet above the roadway. One of the most unique is the bear, surrounded by hunters with bows and arrows (I think the artist was bragging).
In the afternoon we headed west and south across the barren lands around Green River. The small village is the final settlement for a hundred miles west along Interstate 70. The only settlement to the south is Hanksville, around fifty miles away. We were in one of the most isolated regions of the lower 48 states. Our destination for the night was Goblin Valley State Park on the San Rafael Swell. The sunset was glorious (the first picture of today's post was also taken there).
In Jurassic time an ocean embayment extended south from Canada into the Colorado Plateau region. Called the Sundance Sea, it left behind all manner of tidal flats, delta deposits, and coastal dunes. The Entrada Sandstone displays many of these environments, and erosion has carved the rock into a variety of fascinating shapes. For one, most of the arches of Arches National Park occur in the Entrada. At Goblin Valley, the rocks were more thinly-bedded and produced small mushroom-shaped spires that gave the valley its name. If you are a fan of sci-fi flicks, you may recognize Goblin Valley as the setting for some scenes from Galaxy Quest (the one with the little purple aliens and the rock monster).
Looking south from Goblin Valley we could see the high peaks of the Henry Mountains, often described as the last mountain range in the United States to be discovered and explored (in the 1870s). Like the La Sal Mountains described in the last post, they are laccoliths, mushroom-shaped intrusions of magma. It was at the Henry Mountains that the term laccolith was first proposed by Grove Karl Gilbert, a pioneering American geologist.
Stars. Night after night of the most starlit skies I can remember. We were in the darkest corner of the continent, and our nights for the entire trip had been free of moonlight, but the following day the thinnest crescent moon I could remember ever seeing was setting in the west. I noticed later that this first appearance of the moon on June 14 was the ending of the month of Ramadan.
Our destination the following morning was Bryce Canyon National Park. The Colorado Plateau is a remarkable region because for close to a billion years it had been remarkably stable, remaining at or close to sea level throughout Paleozoic and Mesozoic time. But in the Cenozoic this began to change as the land rose above sea level for the last time. During the early Cenozoic Era (60-40 million years ago) the region around Bryce Canyon was a huge freshwater lake. The resulting pink siltstone an limestone layer is called the Claron Formation.
The rocks of the Claron Formation are cut by vertical fractures called joints, and these fractures allow water and ice to widen the cracks and forming the spires of Bryce Canyon. The rock towers are called hoodoos. Sometimes arches and natural bridges will form during this process (natural bridges cover a watercourse while arches do not). Does anyone want to guess what kind of opening this is in the picture below? (Hint: It's named Natural Bridge)
Bryce Canyon is an exceedingly popular national park. Besides the spectacular scenery, it lies in close proximity to Zion and Grand Canyon National Parks and thus makes a "grand triangle" of a tour so beloved by bus companies and tourists on a time budget. The popularity combined with the rush that most people are in to get to the most possible localities means that certain parts of the park are more impacted than others. The free trams go to the most crowded parking lots, and the entire south end of the park tends to be far less crowded and hectic (at least in my experience). If you ever visit, make every effort to go beyond Inspiration Point and see Rainbow Point and the many other pullouts. It will take you no longer to see them than it will to wait for a parking spot to open up at the more popular viewpoints.

By the time we left Bryce that afternoon we were making serious mileage towards home. We crossed the deserts of western Utah and arrived at one of my favorite national parks of all: Great Basin. The park is not a basin, it's a mountain range, the Snake Range. It was established in 1986, although a small portion, Lehman Caves, was made a national monument in 1922. The political journey leading to the establishment of the park was different than most. As I came to understand it (and please, provide some insight in the comments if I have this wrong), there was a desire to have a national park representing the best of the Basin and Range geologic province, but promoters were split between three possible locales! There was the Toiyabe Range in central Nevada, the Ruby Range/East Humboldt Range in the northwest part of the state, and the Snake Range, which got the eventual nod. Purists supported the Toiyabe Range because it best exemplified the unique ecosystems of the Great Basin whereas the other two showed more affinities for Rocky Mountain flora. It was an interesting problem because the Ruby Mountains and Snake Range offered more "normal" mountain scenery along with glacial lakes. They really are a bit more like the Rockies. I suspect that the Snake Range got the nod because it already had the infrastructure for a national park (an extant visitor center, for instance), it had Lehman Cave as a centerpiece, but it also had Nevada's only glacier, and a forest of Bristlecone Pines, the oldest living organisms on the planet.

The park also protects Wheeler Peak (13,063 feet), which is the highest peak entirely within the boundaries of the state of Nevada (the actual high point, Boundary Peak, is a spur on the ridge of a higher peak in California, and it is only about 50 feet higher than Wheeler). There is a spectacular ridge-hugging paved road that reaches the main trailheads at over 10,000 feet.
Great Basin is one of my favorites because it still retains the character of what most national parks once were: havens of serenity and wilderness. The park is generally uncrowded (except for the lines at the visitor center for cavern tour tickets), and mostly undeveloped. There are roads and campgrounds, for instance, but many of the roads are unpaved, and the campgrounds are old style: vault toilets, and no hook-ups. The last time I checked, the campfire programs were actually done around campfires, without screens and PowerPoint presentations. I hesitate to even tell you about this because you might want to go and see it, and it will get crowded like all the rest. Just kidding, go see it. It's beautiful, and the caverns are wonderful too.
The next day was a long drive across Nevada, and we had one more night, staying at Berlin-Ichthyosaur State Park. It's a fascinating place and I would describe it in detail, but I took few pictures, and this post is all about my favorite shots from the trip (you can read some details in this post from a previous trip). The next morning we were homebound and quickly crossed the western desert hills of Nevada. We crossed Anchorite Pass and rolled into our home state of California  In a matter of minutes Mono Lake came into view. We took a break at the Interagency Visitor Center at Lee Vining.
Mono Lake is a singular ecosystem in California, like no other place in the state. It occupies a large tectonic basin, meaning it has no (current) natural outlet. Lots of water flows into the lake via streams from the adjacent Sierra Nevada, but the only way water can leave is by way of evaporation. Because of this, the salt content of the lake is three times that of seawater. Few organisms can survive such conditions, so the ecosystem is pretty straightforward: some algae, trillions of brine shrimp, trillions of brine flies, and millions of migratory and resident bird species. Mono Lake is one of the most important stops on the Pacific migratory flyway.

Unfortunately humans always find a way to muck things up, and Los Angeles worked really hard to mess up this system. It involved building a 200 mile-long aqueduct and an eleven mile-long tunnel under a series of volcanoes to siphon off water from the tributaries that drain into Mono Lake. When the city closed off the streams in 1941 Mono Lake began drying up and lost 45 feet of elevation. The salinity drastically increased, threatening to kill off the shrimp. Lawsuits dragged on for years, but now an agreement is in place to raise the lake to a sustainable level. If only the California drought would cooperate...

The day we arrived the lake was (for me) an unusual shade of turquoise. The clouds were a sight as well. There had been not a great many clouds during our trip. The lack of rain was nice, but the entire route of our trip has been in the grip of an exceptionally severe drought. We wouldn't have minded a drencher if it could have helped.

Our final national park of the trip was in some ways the most familiar, but we didn't see it from a normal angle. Something like 90% of the people who visit Yosemite National Park go to the iconic valley, but the valley makes up only 7 square miles of a 1,000 square mile park. We entered the park at Tioga Pass (9,945 feet) and drove through the alpine meadows of the upper Tuolumne River. After more than 3,000 miles of barren desert environments, the greenery was stunning. We made a final lecture stop at Olmsted Point, which provided a unique view of Half Dome, from upstream.

But that was it. Once everyone realized that we had crossed the headwaters of the river that flows through our community, there was no slowing down. Homesickness is a powerful emotion and it was almost as if our vans took on a life of their own as we rolled down the western slope of the Sierra Nevada to the end of our journey. Like crazed tourists, we had visited 10 national parks, 9 national monuments and recreation areas, and maybe a dozen state parks. We had traversed a geological history encompassing 1.7 billion years of geological events and thousands of years of human history. All it took was 15 days, 3,700 miles, and a great group of students and volunteers!

Come join us some time in the future. We're headed to the Cascades this fall with a five day trip to Mt. Shasta, Lava Beds National Monument, Lassen Volcanic National Park, and McArthur-Burney Falls State Park. Contact me for details...