The Carpeted Dunes of Oregon's Central Coast: The Principle of Unintended Consequences

So how about this plush carpeting on a sand dune? What? It doesn't look like a sand dune? Some people are such skeptics....let's find a trail...

There's the sand, with three or four feet of grassroots on either side.

We are at the north end of Oregon Dunes National Recreation Area near the estuary of the Siuslaw River in Florence. The grass growing on and covering these dunes is European Beachgrass (Ammophila arenaria), an invasive plant that was introduced in the 1920s. It was an excellent example of the principle of unintended consequences. The apparent solution of one problem resulted in a number of others.

There are some very specific problems associated with living along the Oregon coast between Florence and Coos Bay. The forty-mile stretch of sandy beaches and dunes ranges up to three miles inland and any roads or towns built there must contend with the instability of windblown sand and dune migration. The introduction of the European Beachgrass was seen as a way of stabilizing the dunes. In a sense, the grass did the job too well.

The grass has deep roots and spreads rapidly, overwhelming and replacing the native plant species. By anchoring the sand just above the shoreline, new sand blowing in from the beach is trapped in the grasses, causing the foredunes to grow higher and higher. Little of the new sand on the beach gets past the foredune system, and a form of stability is achieved.

Deflation basin in the south jetty area of the Siuslaw River

Without the infusion of new sand, the area inland of the foredune system becomes starved of sediment. The wind blows just as much and carries what sand there is farther inland, sometimes burying the forests growing there. What had been a dune complex with occasional islands of trees and vegetation becomes a deflation basin, a place where sand is removed to the local groundwater level. The wet ground and ponds found there become a stable surface where a thick forest can start growing. The dunes are stabilized to an extent, but much of the dune environment with all the native plants and animals is lost (see the comparison below).

Another problem with many invasive species is that they don't tend to stay where they are supposed to. The desired level of control was achieved in some places, but the grass continued to spread far beyond, invading areas like the Oregon Dunes where open dune environments were still desired. The beach grass is now found on coasts from Southern California to British Columbia. And it is extremely difficult to control or remove.

The grass can be pulled manually (by volunteers most of the time) but roots are always left deep in the sand and the grass soon sprouts again. The shoots have to be pulled seven or eight times before the grass is truly gone. It's hard work. Bulldozers and other mechanical means can be used, but the expenses are high. Some herbicides can be used as well, but the disruptions to the native species can be profound. All in all it is a sticky problem.

The coastal sand dune environment is a fascinating place to visit, and there are many recreational opportunities, but there are also opportunities to volunteer and help achieve a return to the natural conditions that existed before humans tried to mold the landscape to their liking. One place to start is the Oregon Dunes Restoration Collaborative which works to preserve and rehabilitate the dune system.

That's a Huge River! Well, Not Exactly...Sediments in the Siuslaw River Estuary

In the photo above we're on a hill overlooking the Siuslaw River near Florence, Oregon. From this point of view the river looks huge and indeed the channel is navigable and leads to a working marina a mile or two upstream. But looks can be deceiving, and a careful observer will note that the "river" spends half of the time flowing the wrong direction. Like two of the last posts here on Geotripper, the Moon is part of the story...this is a tidal estuary. The Moon has the greatest influence on the intensity of the tides.

There is a Siuslaw River, of course, but it is just not quite this big. It is 120 miles long, starting at an elevation of 636 feet in the Oregon Coast Ranges, draining an area of about 773 square miles. The discharge of the river varies greatly depending on the season. The long-term average is around 3,000 cubic feet per second, but last week when I was there it was a mere 145 cubic feet per second. During the worst of flooding the river can exceed 50,000 cfs. But it is the lower part of the river that is affected most by the tides. During extreme high tides, changes in river level can be noted 26 miles upstream.

An estuary is the portion of a river influenced by tides where there is a constant mixing of salt and fresh water. Estuaries are rich in nutrients and one of the richest biomass producers on the planet. The estuary of the Siuslaw River developed at the end of the last Ice Age. With so much water locked up in glacial ice, sea level was hundreds of feet lower than it is today, and the Siuslaw River occupied a deep channel that continued for miles west of the current coastline. As the ice melted, sea level rose and flooded the river valley, but the Siuslaw River carried vast amounts of sediment to fill the flooded channel, forming the flat level valley we can see today. Additional sediment is added by wind blowing sand from the coastal dunes that line the lower channel (the Siuslaw is at the northern end of Oregon Dunes National Recreational Area).

When I was there a week or two ago, we experienced an intense low tide that exposed some rarely seen sedimentary structures in the channel. When the tides rise, water rushes upstream, and when the tides fall, the water goes out to sea. Flowing over the loose silt and sand, the flow causes the development of gigantic ripples like those in the pictures above and below.

It didn't occur to me at the time, but this is not a natural channel. Because of the ship traffic, the channel is dredged to maintain sufficient depth for the boats to pass through. There are other changes in the last century. The drainage of the Siuslaw is one of the most heavily logged regions in Oregon, and the clearcutting of timber has changed the nature of slope failure and flooding on the river. Trees and logjams used to trap sediment upstream, providing a rich breeding ground for salmon. The logjams were removed and the river scoured the channel to bedrock in many places. One of the most destructive activities was the process of "splash-dam" logging. Temporary dams were built across the river and trees were cut and floated in the reservoir. The reservoir was then dynamited and the resulting flood carried the logs downstream to the mills. The practice, needless to say, was hugely destructive of the salmon fisheries. Over the years the salmon runs declined from hundreds of thousands of fish each year to mere thousands.

Some of the sources I checked pointed out that the Siuslaw once was the second richest salmon fishery in Oregon after the Columbia River. Efforts are being made to improve the environment to build the salmon runs. They'll never be what they were a century ago given the vast changes upstream, but there is a lot of potential for growth of fish populations. In the meantime, it is an interesting place to visit if you are ever lucky enough to find yourself on the central Oregon coast (especially during the present heat wave!).

A Moment of Peace: A Minute Walk Through a Coast Redwood Forest

Give yourself a minute. Despite all the goings-on, despite all the noise, there are peaceful places and moments. Here is one minute of walking through a Coast Redwood forest in Northern California, the South Bull Creek Trail. No narration, no "learnin'", just walking. Enjoy a moment of peace! The geology blogging will resume shortly...

49th Anniversary of the Landing of Humans on the Moon: Science, History, and the Doing of Big Things

The Moon tonight, July 20th, 2018

Today marks the 49th year since humans walked on the moon for the first time. The landing was an important part of my own life, and whenever I am reminded, I am taken back to my childhood. In 1969, I was at a scout camp high in the southern Sierra Nevada. I'm not sure whose screw-up it was that our troop was in the middle of nowhere at the moment of one of humanity's greatest achievements, but that was the way it was. I can remember walking through the pinyon forest between the dining hall and our campsite (they were pretty far apart). I was alone at the time, and I heard the camp loudspeakers crackle on (which was unusual; we usually only heard "taps" and other bugle calls, or the emergency alarm). I heard a scratchy voice say "That's one small step for a man, one giant leap for mankind", and I realized that humanity had just accomplished something big. Something that had never been done before. It had a profound effect on that scrawny kid in the pinyon forest at Circle B Scout Ranch.

I grew up in the early sixties fascinated by astronomy. But it was also frustrating that things were so distant and so unreachable by we earthbound humans. Our own moon seemed impossibly distant, despite the objective laid forth by JFK that we would reach it before 1970.

The other planets in our own Solar System were small disks in our best telescopes, and the moons that circled them mere points of light. At the time I had a postcard from the Palomar Observatory that had pictures of Jupiter and Saturn similar to those below. I spent hours staring at them with a hand lens and later on a microscope, hoping I could make out more detailed features to no avail. The other stars? They were so distant that even in our best telescopes they looked no different, just spots of light. The more I learned about the stars and galaxies of the cosmos, the more impossible it seemed that we could ever reach them. Neil Armstrong, Buzz Aldrin, and Michael Collins changed that. They are heroes of the best kind, courageous men who risked everything to do something that had never before been done.

Of course, Armstrong, Aldrin and Collins didn't build the Apollo Spacecraft, or the gigantic Saturn 5 rocket that sent them into space. They didn't navigate to the moon by themselves. There were thousands of engineers and scientists who did the calculations, designed the modules, and shepherded the spacecraft to the moon, and even more importantly, back home again. The vast majority of scientists and engineers were the product of an educational system that was the best the world had ever seen. And they were driven by a communal sense of purpose. They worked together towards a common goal, and their discoveries and innovations radically changed the world we live in.

Of course our cynicism allows us to point out that once we beat the Russians to the moon, the public pretty much lost interest in the space program. NASA started to fade from the public consciousness, but the system was in place that allowed a series of successful projects that have changed the way we view the cosmos and our place in it. We never sent astronauts to Mars, but we sent rovers. We sent the Voyagers to Jupiter, Saturn, Uranus and Neptune (in a wonderful case of over-engineering, the spacecraft outlived their expected missions by decades). Not even two weeks ago, Voyager 2 passed its 41th year of operation...it is still sending data from 9 billion miles away with an onboard computer that is probably less powerful than one of those Commodore 64 models that I wrote my thesis on in 1985. Voyager 1 is also continuing to operate.

Today we see our Solar System in stunning detail, in a way that would have been unbelievable to that child of the sixties. We know the surface of Mars in more detail than we know the surface of our own planet. We've explored the moons of Jupiter and Saturn, discovering strange worlds with vast oceans hidden beneath icy crusts, volcanoes of molten sulfur, and lakes, rivers and oceans made of liquid methane. We've peered through the clouds of Venus, and just a few years ago, we photographed and analyzed the hidden side of Mercury that we missed on the first mission three decades ago. We saw Pluto up close for the first time only two years ago, and we've orbited the two largest asteroids, Vesta and Ceres.

The Hubble Space Telescope was the other game-changer. It has shown us the rest of the Universe with a clarity that was unimaginable four decades ago. We can see star nurseries and nascent star systems that provide us visual evidence of how our own Solar System formed. The Hubble and other high-tech units have now seen objects that formed a mere half billion years after the origin of the Universe itself 14 billion years ago. And we are only a few years away from the launch of an even more powerful telescope, the Webb Space Telescope.

This is the heritage of a country that undertook an audacious program of exploration under the leadership of JFK, and which succeeded through the exploits of courageous men like Neil Armstrong, Buzz Aldrin, and Michael Collins. What do our children dream of today? Is our education system inspiring them to strive for incredible things, or is it teaching them to be unquestioning automatons in a factory or office? Are we teaching them to be curious about the world, or teaching them how to take a multiple-choice assessment test?

Our teachers and professors are working in a toxic environment these days. How else to explain things like a political party in Texas in 2012 that added a plank in their platform that says "We oppose the teaching of Higher Order Thinking Skills, critical thinking skills and similar programs that are simply a relabeling of Outcome-Based Education which focus on behavior modification and have the purpose of challenging the student’s fixed beliefs and undermining parental authority."?  Is that what we have come to?

I refuse to believe that. I believe that adventure still awaits us as a people. As I start a new school year next month, I am as excited as I have ever been to have the opportunity to introduce my students to an incredible Universe. And almost every teacher I know feels the same way.

It is a sense of adventure that Neil Armstrong would have understood...

This is an abridged and updated version of a post from August 25, 2012 marking the passing of astronaut Neil Armstrong.

Conjunction of Inanna and Theia's Child Tonight

There was quite the spectacle in the heavens tonight, the conjunction of Inanna and Theia's child. Obviously some explanation is needed here since most people refer to these heavenly bodies as the planet Venus and the Moon. Inanna was the Sumerian name for the brightest planet, and they may have been the first people to surmise that the Morning Star and the Evening Star were the same object. The goddess they worshipped morphed into Ishtar and influenced the idea of Aphrodite. Venus was the Roman version of the deity.

Theia refers to the Mars-sized planetoid that collided with Earth early in her history that resulted in the formation of the Moon. The event probably took place about 4.51 billion years ago, very shortly after the formation of Earth itself. The hypothesis explains many of the odd chemical characteristics shared by the Moon and the Earth.

This picture was taken 45 minutes earlier than the first. Note the change in the position of he Moon (it moves much faster against the background.

In any case it was a beautiful sight tonight in the western sky shortly after sunset. I took pictures over a period of about 45 minutes and the relative position of the two celestial bodies was noticeably different.

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...

River Otter on the Tuolumne

I am quite lucky to have the Tuolumne River in my backyard. The river rises in the highest regions of Yosemite National Park, flows through incredible and largely unknown gorges that rival the Grand Canyon in depth. Water is trapped in a series of reservoirs including Hetch Hetchy and Don Pedro, and at that point the river could have been cut off the way the San Joaquin River was destroyed. But water agreements have kept a minimum flow, so the river flows onto the floor of the Great Valley and maintains a continuous riparian habitat all the way to the Sacramento Delta. The river bed has been severely altered, first by the gold miners, and later by quarry operators and farmers. But portions are in the process of healing, and in places the stream is starting to resemble its earlier incarnation as a wild river.

I saw River Otters (Lontra canadensis) for the first time just two or three years ago, and I'll see them two or three times a year when I stroll along the river trail. This morning the water level was low and river transparent, so I saw what I thought was an immense fish maybe three feet long deep in the water. I turned on the camera to get video and hit the wrong button, but then the "fish" surfaced and I realized I was watching an Otter. I got the video going correctly and got some of the best "footage" so far.

River Otters are making a comeback in the rivers and streams of the San Joaquin and Sacramento Rivers and across the Bay Area. I'm so glad some of them have made it here to my little corner of the river! For more information on otter sightings and ecology, check out the River Otter Ecology Project.

Home from Back of Beyond: Images of a Harsh Country, Part Two

The photo above encompasses so much of what captivates me about the southwestern United States. A trail formed from a natural weakness in the rock providing access to an otherwise inaccessible cliff to who knows where? To be fair, hundreds of thousands of people know where the trail leads, but I like the mystery of the image. The thing is, many people DO follow this trail every year, but they may not appreciate the fact that the last time this surface was exposed to the atmosphere, it was 200 million years ago, and on the slip face of a coastal dune. Some of the irregularities highlighted by the shadows in the picture could literally be the preserved footsteps of dinosaurs, other reptiles, or amphibians.

I am slowly working on a short series of posts with my favorite images from our recently completed exploration of the Colorado Plateau and surrounding provinces. I took 1,400 photographs, so it's a bit difficult to choose between them! As we pick up the narrative, we are eight days into a fifteen day trip. As seen in an earlier post, we'd already been to the Mojave National Preserve, Zion National Park, Grand Canyon National Park, Bear's Ears National Monument, and Mesa Verde National Park. As we left Mesa Verde, we needed to find a way over the San Juan Mountains, a major range within the Rocky Mountain chain.

Because of a major wildfire in the drainage of the Animas River above Durango, we had to find another route over the mountains, so we headed instead to Lizard Head Pass (10,222 feet/3,116 meters), which divides the drainage of the Dolores and San Miguel Rivers. There was a beautiful profile of the high peaks from the summit. The brightly colored rocks above the tree line are volcanic, part of the rhyolite caldera eruptions that were taking place around 35-30 million years ago. Mineralization related to the volcanic activity resulted the emplacement of gold and silver deposits. The old mining towns like Ouray and Telluride are picturesque, but the pollution relating to the mining is a sad heritage.

Near the town of Ouray, one of the old mining camps, there is a difficult-to-see waterfall called Box Canyon Falls. The 200 foot high falls are practically hidden in a deep slot canyon, but the slopes above reveal a spectacular angular unconformity. The underlying vertical layers are more than a billion years old, but erosion planed off the rocks and in Devonian time almost 400 million years ago new sediments were draped over the older rocks. The uplift of the San Juan Mountains caused further erosion, exposing the unconformity that represents almost a billion years of missing history.

Black Canyon of the Gunnison is possibly the most bizarre canyon on the continent. It is a nearly vertical gorge that cuts through what is essentially the top of a mountain instead of having been carved through softer rocks that are exposed nearby. The Gunnison River was forced into the present channel by a series of lava flows that diverted the river from a "normal" course. Around 2-3 million years ago the landscape was uplifted, and the trapped river cut down through all the rock in its path, including the extremely hard gneiss and granite that make up the canyon walls in the park. It's not the deepest canyon in the country, but no other canyon combines the depth and steepness of Black Canyon. It is more than 2,000 feet deep in places, and in one place it is only 1,100 feet wide.

The Painted Wall (above) in Black Canyon is the highest sheer cliff in Colorado at 2,250 feet. The rocks exposed in the face of the cliff include 1.7 billion year old gneiss and schist with numerous intrusions and dikes of lighter colored granitic rock, including extremely coarse-grained pegmatite.

Late in the day we headed down one of the most spectacular roads in North America, Highway 128, which follows the Colorado River from near Interstate 70 to the outskirts of Moab, Utah. While mostly confined to a deep and narrow gorge of sandstone cliffs along the river, there is a moment when the canyon opens up and there is an awe-inspiring view of the Fisher Towers and the La Sal Mountains.

The La Sal Mountains are an anomaly in the generally horizonal landscapes of the Colorado Plateau. Between 28 and 25 million years ago, plumes of magma worked their way almost to the surface, intruding laterally between the sedimentary layers, and causing them to swell upwards like a series of blisters in the crust. The intrusions are called laccoliths. Exposed now by erosion, the igneous rocks reach elevations of almost 13,000 feet.

We arrived at our campsite in Arches National Park as the sun approached the western horizon. I don't think there is a more spectacular place in the country to roll out a sleeping bag. The view from the group camp extends for miles in every direction. There is also a beautiful arch, Skyline, visible from camp (below). The arch more than doubled in size in 1940 when a huge chunk of rock fell from the opening.

The landscapes in and around Arches and Canyonlands National Parks are almost beyond description. We spent two days in the area, and one of our stops was a rock art panel that is so delicate and fragile that I can't believe that it still exists 30 years after I first discovered it. Why? It's easily seen from the paved road leading into Canyonlands. But without signs and arrows pointing the way, people miss it. The first of the images are pictographs (below), those examples of rock art that were painted onto the sandstone. The ghostly figures and small hummingbirds are almost nightmarish in their imagery.

The other images are petroglyphs, the ones carved directly from the rocks. They depict some stylized bighorn sheep and other creatures. The panel has been somewhat damaged, possibly by natural erosion, but vandals have also done their evil work here.

Canyonlands National Park has many incredible vistas, but my favorite is the one that is framed by Mesa Arch (below). The arch is relatively small, but it frames the La Sal Mountains and pillars and cliffs of the Colorado River section of the park (the Green River forms meets the Colorado inside the park). Mesa is a popular short trail, and crowds are especially thick in the early morning when the sunrise can be photographed through the opening. You've no doubt seen an example on just about any nature-based calendar!

Pictures of Canyonlands are often mistaken for the Grand Canyon, but this section of the river includes only late Paleozoic rocks and thousands of feet of Mesozoic layers that are not seen at Grand Canyon. It is not as deep, but it is deeply colorful. It's hotter country in the summer, and there aren't many sources of water. Travel away from paved roads is more challenging than your "average" national park.

After we explored the Island in the Sky District of Canyonlands and Dead Horse Point State Park, we headed back to Arches for one of the greatest excursions on our entire trip, the hike to Delicate Arch for the sunset. The trail (a picture of which started this post) climbs 1.5 miles to an iconic overlook of the famous arch. I would love to say that the hike is an awesome desert wilderness trek where one can discover one's self in the isolation and serenity, but as author Edward Abbey feared in his 1968 book Desert Solitaire, the trail (and much of the rest of the park) has been taken over by industrial tourism. There is a large paved parking lot, and hundreds of people make the trek every evening.

Frame Arch view of Delicate Arch

The crowd at the top was rowdy, in large part because there are always selfish individuals and groups who insist on standing within the arch for selfies and group photos, spoiling the view for everyone else. I didn't have the heart to listen to the ruckus (I most certainly would have contributed, shouting at the jerks in the arch), so I headed instead to my favorite little arch in the park, Frame Arch. Frame is a small arch just above the trail only a few dozen yards from the Delicate Arch viewpoint. Most people pass it by in their race to get to more famous arch around the corner. What most of them don't realize is that Frame Arch has a great view of Delicate Arch, but also of the La Sal Mountains and Salt Wash. And I had the arch to myself for quite awhile even as hundreds of people were gathered just around the corner.

The La Sal Mountains and Salt Wash through Frame Arch

I had to think of my students though. There were a dozen of them who had hiked ahead of me, and they had to be worrying that their old overweight professor was passed out somewhere down the trail dying while they were enjoying the view. So I climbed down from the arch and back onto the trail and walked the last few yards to the overlook. I patiently waited while the jerks stood for their pictures in Delicate Arch and finally got a picture sans people as the sun settled into the horizon.

Our trip wasn't over. We had five more days and two more states to traverse. More favorite pictures soon!