The Deepest Pass in North America, and Finally Taking THE Aerial Tramway

Last weekend I was having lunch in Palm Springs. That might sound, I dunno, elitist or something, but we were actually in Beaumont, and we hadn't seen the city of golf courses and the idle rich in decades so there we were. Driving down the main drag, we saw the Palm Springs Art Museum, and said "why not?" and paid a visit. Several hours later I had seen most of it and decided to walk around the grounds and discovered a trailhead! I read the sign, and found it was the Skyline Trail, which climbs around 8,000 feet up the flank of San Jacinto Peak (10,804 feet) in twelve miles. It's said to be one of the most difficult and dangerous in the country, especially in the summer when temperatures can soar to 115 degrees. There's no water or shade for most of the climb.

Well, I had my hat. I had half a bottle of water. It was 4 PM and only 103 degrees and no one knew where I was. So off I went up the trail. At this point you may be thinking that I am about to describe a real disaster of bad judgment and pointless rescue, but no, I'm not quite that stupid (Mrs. Geotripper may have an alternate opinion on this). I went up maybe 200 yards, high enough to get some pictures of the city over the tops of the palm trees on the adjacent golf course, and headed back down to the museum to cool off.

But just the thought of the trail had reawakened a great many memories of my days as a teen in Southern California. I was practically indestructible in those days and was recognized as the fastest long-distance hiker in my high school. I climbed Mt. Baldy via the "old" trail that climbed 6,000 feet to the top, and summited at least fifty other peaks. But I never walked to the top of San Jacinto starting from the desert floor. At the time, I hadn't heard of the Skyline Trail, but had learned of a climber's route up Snow Canyon, but never found the time. All I knew was that San Jacinto Peak was a very high mountain that rose from desert plains only a short distance above sea level. The escarpment of San Jacinto is one of the highest and steepest in North America.

There is a mountain ridge across from San Jacinto that is even higher. San Gorgonio Peak is the highest mountain in Southern California at 11,499 feet. The pass between the two mountain ranges tops out at just 2,600 feet, meaning that San Gorgonio Pass is probably the deepest pass in North America, at nearly 9,000 feet. It's nearly twice as deep as the Grand Canyon, and deeper than the deepest canyons on the continent, Hells Canyon of the Snake River, and Kings Canyon in the Sierra Nevada.

Mrs. Geotripper had some sympathy for my vague feelings of disquiet about not finishing the hike and offered that I should just take the Palm Springs Aerial Tramway up to Long Valley where the trail ends. I could accomplish the same thing as the killer hike in about 12 minutes for only $25. I struggled for a moment with my lifelong philosophy that incredible views have to be earned by sweat, but then said yes. We headed up Chino Canyon to the base of the tramway.

For those of you who are not familiar with the tramway, it is quite an engineering feat. The tram begins at 2,643 feet in the Lower Sonoran life zone and climbs to 8,516 feet in the Canadian or Hudsonian zone. It is two and a half miles long and is supported by five towers, the tallest of which is more than 200 feet. It was constructed in 1963 and with no roads or trails in the rugged terrain, much of the construction was accomplished with helicopters.

It was my first time on the tram, but not my first time at the Mountain Station at the top. Many years ago I had walked to the station from the trailhead in Idylwild on the other side of the mountain. It was one of those classic hikes where the ten or so of us teens went wandering off from camp without really preparing for a long hike only to find as the sun was setting that we had a single flashlight for the whole group for the three mile hike back in the dark. The minister who was our group leader was kind of frantic as the night wore on with a large part of his group missing. It was a fine adventure all those years ago.

We were lucky last weekend, because the atmosphere was reasonably clear and the view was spectacular. Joshua Tree National Park stretched across the valley beyond Palm Springs. We could see the deep canyon of the Whitewater River, the main canyon draining the east side of San Gorgonio, now part of Sand to Snow National Monument. At our feet we could see some of the 4,000 turbines of the San Gorgonio Wind Farm in the pass (below). The pass is one of the windiest spots in all of California, owing to the height of the surrounding mountains and relative narrowness of the pass.

There was also a panorama above, as we were standing along the edge of a high-altitude plateau of the San Jacinto massif. The relatively gentle slopes and valleys of the highland are a relict surface of the landscape that existed before the mountains rose thousands of feet along the bounding fault lines.

All of this leads to a question: what geological processes combined to form this extraordinary landscape? Actually, it has to be two sets of questions, because one needs an explanation for the landscape, but also an explanation for the rocks that underlie the landscape.

First, some regional context. The San Jacinto Mountains are part of the Sierra Nevada, sort of. They are officially described as the northern end of the Peninsular Ranges, which extend all the way down the Baja Peninsula for another 700 miles south of the border. But the rocks themselves originated along the huge Mesozoic subduction zone that extended from Mexico to Canada. There was a continuous mass of granite that included the Sierra Nevada, the Salinian Block, and the Peninsular Ranges batholith. Later on the Salinian Block was carried northwest along the San Andreas fault, and the Peninsular Ranges more or less ended up in the location from where the Salinian Block had been removed.

The rocks themselves are what most normal people would call "granite", light-colored (feldspar and quartz-bearing) plutonic rocks overall with black specks of biotite mica or hornblende. Geologists will concede to calling the rocks "granitic", but look at the proportions of feldspar varieties and quartz to come up with some more imposing names like quartz diorite, quartz monzonite, and hornblende diorite. These rocks formed in the subduction zone where oceanic crust and continental sediments were pushed so deep into the mantle that some of the material melted and rose through the crust as magma plutons. These masses rose until they reached some form of buoyancy and cooled slowly over tens of thousands or hundreds of thousands of years, forming the coarser-grained granitic rock. Later on erosion removed the miles of overlying crust to expose the sparkling plutonic rocks.

Source: https://pubs.usgs.gov/sir/2011/5156/

As the granite is released from the great pressure of deep burial, the rocks expand and crack, forming prominent vertical joints. The joints are wedged apart in the winter by ice, with some rocks falling away and others remaining in place as spires and towers on the steep slopes.

During the tram ride up the mountain, the rider is treated with some awesome views of the granitic rocks. In many places the granite has been pierced by light-colored dikes. These were silica-rich masses of the last bit of molten material that filled cracks in the final stages of cooling. Some of the dikes are pegmatites, made up of unusually large (inches across, sometimes a foot or more) crystals of quartz, feldspar, and sometimes gemstones like tourmaline, garnet, topaz, or beryl. The gemstones are still mined in other parts of the Peninsular Ranges. I really wanted to call for the tram to stop and let me down a rope to check out the exposures!

The next picture below shows an especially prominent dike that has resisted erosion and now stands out in relief. It actually looks like some of the "cartoons" I use in lab to teach sequence of geologic events. Which came last, the grey rock, the horizontal white dikes, or the vertical dike that stands out in relief?

The final part of the story is in some ways the most difficult. How did the Peninsular Ranges become mountains, and why is there such a deep pass between them? I don't know that I have a great answer to that question, but one can assume that fault lies with the faults. Several major faults pass through the pass, including the most familiar of all, the San Andreas. But the San Andreas is a strike-slip, or lateral moving fault, not one that leads to vertical uplift. There are complications in the path of the fault though that can explain why there are mountains here.

Source: https://pubs.geoscienceworld.org/gsa/geology/article/37/2/191/519461/the-enigmatic-san-gorgonio-pass

If the trace of a strike-slip fault is absolutely straight, over time the fault won't cause much in the way of uplift as it moves. The trace of the San Andreas through the Carrizo Plains farther to the northwest demonstrates this (the fault has only produced low hills there). But if there are bends or turns in the path of the fault, local areas of extension or compression can develop that will cause vertical uplift (or basin subsidence). The Peninsular Ranges form the western margin of the Coachella Valley, which is the northern extension of the fault basin (and divergent boundary) of the Gulf of California. The continent here is ripping apart, and the valley has sunk thousands of feet. In at least one way, the San Jacinto massif can be thought of as forming from the sinking of the adjacent valley rather than being "pushed" upwards, although there may be some element of that going on as well (thrust faults are present on the north side of San Gorgonio Pass).


The San Andreas fault was visible from the tramway. The zoomed image above shows Highway 62 where it passes through the Little San Bernardino Mountains on the way to Morongo Valley. The fault passes along the base of the mountain range.

We had a dinner appointment elsewhere, so the time to descend from the mountain top came much too soon, but down we went, dropping 6,000 feet in 10 minutes. My ears popped a couple of times. It was an awesome experience, but I still had the disquieting feeling that these incredibly steep and rugged cliffs were not a place for humans. They are more the domain of the hawks and condors.

A small postscript: "That's AMAZING!" I miss Huell Howser and his unique explorations of California. Here is his 1997 episode that included the Palm Springs Aerial Tramway as well as the 13 mile long tunnel underneath the San Jacinto Mountains that was constructed to deliver Colorado River water to Southern California:

https://blogs.chapman.edu/huell-howser-archives/1997/01/08/mt-san-jacinto-californias-gold-804/

Why Science Matters: March For Science 2017

A bank robber can make a lot of arguments about why he or she should be allowed to rob a bank. "The money in the bank is just sitting there, it's not aiding the economy by being circulated", or "By taking this money and spending it, I'll be creating jobs", or "But I'll give some of the money to charities". A bank president, and for that matter, the people who have been robbed, would never agree that this justifies stealing the money. So why would anyone acquiesce their right to clean water and air, safe food and drugs, and their very environment to those who would steal those things from them? Sometimes it's because they are kept in the dark about the dangers that they face. Ignorance is a valuable tool for those who would profit off of our birthright to clean air and water, and a livable environment.

Sometimes the dangers in our environment are obvious. Earthquakes, floods, or volcanic eruptions are events whose existence cannot be denied. In other situations the problem is not so obvious. Lead in water causes damage over longer terms. Cigarettes or radiation may take years to produce lung cancer. The loss of ozone or rising world temperatures have taken years to manifest changes in our living environment. Such gradual changes are harder to recognize in our day to day lives even though the changes are very real. Yet these phenomena can kill people every bit as much as an earthquake, just not all at once. The recognition of these dangers are critical to keeping society safe, but there is a serious problem. Someone is making money by keeping society ignorant.

Corporations make their profits selling cigarettes. They make profits by cutting corners in food safety and by avoiding air and water pollution controls. They make profits by maintaining dependence on fossil fuels as a primary energy source. We live in a society based on capitalism, but unrestrained capitalism is ultimately not in our best interest. Corporations cannot be trusted to police themselves, a fact they've proven over and over.

We instituted federal and state governments to protect us and to work for the common good. When corporations killed and injured citizens, the government stepped in to limit the damage by regulating dangerous industries. And it worked. The workplace environment is much safer these days than it was a century ago. Politicians, for better or worse, represent us and design the laws and the government programs that protect our citizens from harm. They hear from lobbyists all the time as they make decisions on legislation and sometimes they hear from constituents. But there is another voice, and I've always taken it for granted that it would be heard: the voice of science.

Why is science needed? Scientific research is the unbiased source of information and data on issues of environmental protection and safety. Corporate scientists may do important research, but the profit motive ultimately influences their findings. It is only through independent inquiry that we can trust the accuracy of research. In so many ways, government-funded scientific research has been a huge success, one that has driven innovation in our economy and made our society one of the richest and safest in human history. The U.S. Geological Survey, the Environmental Protection Agency, the Centers for Disease Control and NASA have done incredible work, and have informed public decision-making for many decades. And...they have led the human adventure. Without government funding for the big endeavors, the exploration of space, the exploration of the interior of the atom, the inner workings of the Earth, we would be unable to continue the quest for knowledge.

So why are scientists marching in the streets? Because unbiased scientific research is under attack. Corporations have finally achieved their aim and have one-party control of Congress, the Presidency, and the Supreme Court. There are intensive efforts underway to destroy the effectiveness of independent government-sponsored research, with draconian cuts to the EPA, CDC, USGS and other science-based government institutions. We have a president and a Congress who deny that global warming and climate change are even happening, despite the ongoing damage occurring in coastal environments and alpine habitats. The spread of tropical diseases is accelerating. Millions of trees across the American west are dying.

I've lived through the birth of the environmental movement in the 60s and 70s, and felt great pride that my country took the lead in designing laws that protected people from toxins and poisons in the air and water. I am dismayed that we must fight these battles all over again, but unfortunately we don't get to choose the times we are living in. So it was that I took to the streets on Saturday.

It was a marvelous thing to see tens of thousands of people in the large urban areas like LA, San Francisco, Chicago, and New York, but I was even more inspired that marches for science took place in small towns all across the country, and across the world (scientific knowledge does not stop at international borders, even if there are walls). I marched in the small California town of Hemet along with perhaps forty or fifty people. There were smaller such marches all across the country. People understand the need for unbiased research, and are ready to fight for it politically.

Ansel Adams said it well: "It is horrifying that we have to fight our own government to save the environment". And yet that is the place to which we have come, although I find hope that those who still work in the EPA and other government institutions are in agreement with the aims of the March for Science. The protests must continue, and citizens need to hold the feet of their representatives to the fire. Unbiased scientific research must continue for the sake of our health and the environment in which we live.

As I went through the pictures of the march, I noticed the huge high ridge of San Jacinto Peak in the distance above town. Southern California is largely a desert or near-desert, but the high mountain ridges surrounding the arid valleys reach elevations in excess of 10,000 feet. They are islands above the desert, and they are under assault from the ravages of global warming. The continuing drought has caused intense wildfires that have stripped away the cool conifer forests. The environment is changing in ways that we are only just beginning to recognize, and we need the research and data to understand the future and how to prepare for it. It's not of the sake of some endangered butterfly, although that is important too. It's for the sake of all of us humans, who will pass this planet on to our children. We need to care.

The Other California: When is a Peninsular Range not a Peninsula?

Answer: When it is in Alta California instead of Baja California.

My previous post included a mystery picture of a dome in California, and those who went out on a limb and guessed at the location gave some excellent possible answers: Yosemite, Hetch Hetchy, other Sierra Nevada sites, and Castle Crags up in the Klamath Mountains. But...there is another granitic mountain range in California that reaches elevations in excess of 10,000 feet, and includes some alpine forest environments, incredible views, wonderful backpacking trails, and some excellent technical rock climbing. The dome in the last post is Lily Rock, a rather large outcropping of granitic rock that rises over the mountain town of Idylwild in the San Jacinto Mountains at the extreme north end of the Peninsular Ranges of California.

The Peninsular Range of California extends from San Gorgonio Pass on the north to the very southern tip of Baja California in Mexico. There is no peninsula as such in Alta California, but in a few hundred thousand years there will be one, as the adjacent Salton Trough continues to open up, allowing the Gulf of California to expand northward.

San Jacinto Peak (10,834 feet) is the highest point in the entire range, and rises in spectacular fashion from San Gorgonio Pass, with relief approaching two miles. Only Telescope Peak in Death Valley, or parts of the Sierra Nevada crest over the Owens Valley come anywhere close.

Lily Rock (sometimes Tahquitz Rock) is visible in the picture above, a little bit left of center. Local technical rock climbers know it well, honing their skills here when they can't get to the more famous cliffs of Yosemite. Tahquitz Peak rises to an elevation of 8,846 feet to the right of the dome. Marion Peak and other peaks on the high ridge of San Jacinto itself are visible on the left. A network of trails criss-cross the high plateau between the peaks, which is protected as San Jacinto State Park.

This was a mountain range of my youth. I spent many weekends in my teen years exploring as many corners of the wilderness as I could, and I loved it dearly. But when I visited Idylwild a few weeks ago, it was the first visit in perhaps 30 years. A few things have changed. Back then, the long ridge leading from San Jacinto to Santa Rosa Peak, about 30 miles to the south, was a largely unknown roadless area with hidden springs, pockets of incense cedar forest, and a few island forests of ponderosa and fir. In 2004, the entire range won protection as Santa Rosa and San Jacinto National Monument, administered jointly by (try to follow me here), the Bureau of Land Management, National Forest Service, the Agua Caliente Band of Cahuilla Indians, the California Department of Parks and Recreation, the California Department of Fish and Game, other agencies of the State of California, and private landowners. I'm glad the region has earned federal protection, but I'm not sure I would want to sit in on management meetings!

On clear days, the views from the San Jacinto Mountains are simply stunning. We had a clear day that allowed us to look down on Hemet and Perris Lake off to the west, with the Santa Ana Mountains in the far distance. This is some wonderful mountain country within a short distance of the huge population of Southern California. If you think you have to go to the Sierra to see alpine granite landscapes and splendid isolation, you don't necessarily have to go that far. Check it out!

The Other California is a blog series on the hidden geological gems of my wonderful state.