Mammoth Mountain and Mammoth Lakes are Beautiful, but in a Seismically Active Zone

As most people know, over the past few decades, weather patterns in California have tended toward drought. In addition, the wildfire season extends from at least July until November. One of the hardest hit areas, regarding smoke impact is the Sierra Nevada. Fires tend to start on the western slopes of the Sierra, while prevailing winds blow the smoke to the east. That phenomenon can cover the prime recreation areas of Yosemite, Inyo and Mono Counties for weeks or even months at a time.

Global pandemic or not, huge crowds descended on the Town of Mammoth Lakes and all the surrounding area for the Fourth of July holiday 2020. Young athletes came to town by the hundreds, expecting to enjoy clean air and high altitude training. Many are disappointed by the lung-searing smoke that soon covered the area for much of the summer. With only two supermarkets in town, even staying safe while buying food can be a daunting task. In order to beat the crowds and smoke, we planned our annual visit to Mammoth Lakes for late June. With any luck, the air would still be clear and the holiday crowds would not yet be in town.

On June 27, 2020, Carrie and I arrived at the Mammoth Mountain RV Park for a four-night stay. With a trip distance from Simi Valley of exactly 300 miles, towing our new fifth wheel required over six hours of travel time. With an elevation at the RV Park of over 7,500 feet, we knew it would take a day or two to acclimate. For most of the first day, we stayed in camp, enjoying the fresh air and breezy weather. Neighbors in RV parks like to talk. In this case, our maskless neighbor approached too close for my comfort. Even outdoors, no one knows how far virus particles can travel on the wind.

In June 2020, we were all learning about airborne viruses, social distancing and the value of wearing a mask in public. Tiny Inyo County, with a full-time population of around 11,000 had registered only a few cases of the dreaded Covid-19 virus. Many people still thought there were “safe zones”, where the virus could not reach. Having studied the “Spanish Flu” pandemic of 1918, I knew better. Still, many people walked around both the campgrounds and the town in large groups. Many shunned masks altogether.

On our second day, we drove up Main Street and through the largely deserted Town of Mammoth Lakes. Turning right on Minaret Road, we could see crowds of people retrieving take-out orders from inside the Mammoth Brewing Company. In order to enjoy their meal, most customers stayed crowded on the nearby outdoor benches. To me it looked like a dangerous petri-dish of potential infection. Several weeks after the July Fourth holiday, the infection rate in Mono County spiked for the first time. Virus testing determined that infected restaurant and other food workers drove those numbers up. Apparently, mountain air does not provide immunity from viral infections.

As of January 2020, Mono County is under a regional "stay at home" order, thus prohibiting short overnight stays for recreational purposes. Although condominium owners may visit and stay in their own units, they cannot rent them out on the formerly lucrative short-term rental market. Keep in mind that many recent condo owners purchased their units based on the concept that short-term rentals could pay their mortgage. If the "stay at home" order continues for both the winter and summer seasons of 2021, expect a wave of condominium foreclosures to follow.

Continuing our excursion up Minaret Road, we passed the Mammoth Scenic Loop, which is neither “scenic”, nor a “loop”. After a significant earthquake swarm in the early 1980’s, the road was initially designed and built as the “Mammoth Lakes Volcanic Escape Route”. Escape what, you might ask? Escape a potential phreatic eruption or toxic gas ejection, if Mammoth Mountain were to erupt. Real estate and business interests soon squashed the “Escape Route” moniker, preferring to promote the obscure and misleading “Scenic Loop”. After the 1980’s, despite the ongoing seismic risk, thousands of condominiums and second homes appeared all over the town of Mammoth Lakes. As seismicity declined, real estate prices rose to unprecedented heights.

If you shop for real estate in Mammoth Lakes, do not expect your agent or broker to mention the Long Valley Caldera. According to Wikipedia, “Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about 20 miles long, 11 miles wide, and up to 3,000 feet deep”. According to experts on the subject, the caldera contains 240 cubic miles of magma. If asked about the threat, most locals will shrug and say that the eruption that created the caldera, was 760,000 years ago.

In other words, do not worry about toxic carbon dioxide CO₂  gas discharging from the South Side Fumarole just above the town. Carbon dioxide is about 1.5 times the weight of air, which makes it heavier. If released into the atmosphere it will seek to concentrate at lower elevations. Despite cascading waves of CO₂ emanating from the fumarole, the USGS claims that the Horseshoe Lake tree-kill area is caused solely by CO₂ flowing up from the ground. Other than warning visitors not to walk their dogs into depressions or to lie down in the Horseshoe lake area, the ongoing asphyxiation risk to humans and animals is accepted as “normal”.

Continuing up the road, we arrived at the parking area for what used to be “Chairlift #2”. As with most landmark names recognizable from the early days of the Mammoth Mountain Ski Area, the old “double chair” was replaced with a mega chairlift named “Stump Alley Express”. In late June, there was not a trace of snow near the parking area, but there was plenty of weather activity. As we approached on Minaret Road, a huge cloud of volcanic ash and dust descended the mountain and across the road. With my vehicle window open, the tiny shards of glass and volcanic dust filled the interior and pitted the front window.

In all, three waves or vortices of volcanic dust descended the mountain and across the road. At that time, I did not know that the Mammoth Mountain Fumarole was almost directly above our location. Therefor, I did not realize that we may have witnessed a CO₂ gas emission from the mountain. As the toxic gas descended the slope, it mixed with the air, kicking up even more dust and volcanic glass particles. After seeing how violent a relatively small gas emission from the fumarole could be, I pondered what an actual pyroclastic flow from Mammoth Mountain might look like. Unless preceded by smaller "warning events", a larger eruption would leave no time to search for the “Volcanic Escape Route”, let alone a “Scenic Loop” leading to supposed safety at Highway 395. In past years, smoke from fires and elevated CO₂ levels had made us gasp for breath at Mammoth Lakes. Luckily, this time the volcanic dust cloud passed by without too much damage. To see a short video of the incident, click HERE.

Not stopping at the Main Lodge, we continued up Minaret Road to the Minaret Vista Entrance Station. The ranger informed us that the Devil’s Postpile National Monument was filled, so we looped around and ascended the San Joaquin Jeep Road, also known as Lookout Point Road. At the top of that short road was a parking area and a stone platform appropriately named Minaret Vista. Eschewing the confusion of unmasked people mounting the stairway to the vista point, we walked to the edge of the parking area and took in the view.

To the southwest was the imposing sight of Mammoth Mountain, elevation 11,053 feet. Beyond the valley created by the Middle Fork of the San Joaquin River, and dominating the western horizon were “The Minarets”. Although the jagged, saw tooth range features several named peaks, most people prefer to lump them altogether as if they were a single entity. Even in late June, many of the steep canyons were filled with ice and snow. After dodging several more maskless individuals in the parking area, we drove back to the RV Park.

The following day, we retraced our route up Minaret Road, but this time we took the “Volcanic Escape Route” to Highway 395. About halfway up the "Loop" and a half mile off the road are the Inyo Craters. By some estimates, the twin craters sprang forth in the mid-14th century. Due to excess mineralization and possible CO₂ intrusion, the lake in the larger of the two craters is a milky turquoise blue. Hiking maps of the area published in the 1980's show the craters as being dry, so their small lakes are among the youngest permanent water features in the Sierra Nevada.

After proceeding north for less than two miles on Highway 395, and just short of Obsidian Dome, we turned northeast on to Owens River Road. Soon, the pavement ended, and we were on a gravel road. Somewhere along that road Deadman Creek became the Owens River. As the river meandered through a broad, flat valley, it also picked up the name Dry Creek. In the confusion of names and myriad creeks, it was easy to lose our way. After passing the local landfill, we missed the left turn at Owens River Road. Thus, our new road was Hot Creek Hatchery Road, also known as Whitmore Tubs Road. As you might guess, with all these conflicting names, a detailed local map is recommended.

Arriving at the paved Benton Crossing Road, we headed northeast to Benton Crossing itself. There Brown’s Owens River Campground sits next to the myriad creeks that comprise the upper reaches of the Owens River. Realizing that we were getting farther away from our own campsite, we headed back on Benton Crossing Road, which thankfully does not change names before its dead-end next to the Green Church and Highway 395. Unseen along Benton Crossing Road are many nearby hot springs. There are no signs along the road to tell you where they are. So many of the hot springs had been trashed over the years, all roadside signage was removed. Only those with local knowledge or a topographical map can find most of them today.

From our reentry on to Highway 395 North, we passed the “Mammoth Yosemite Airport”, which is near Mammoth but thirty-five miles from the Yosemite Tioga Road Entrance Station. To me, the “Mammoth Yosemite Airport” moniker is a deceptive renaming of the old Mammoth Mountain Airport. Airports, like any physical object can exist in only one place. In 1997, local politicians in Mammoth Lakes tried to turn the windswept and dangerous Mammoth Airport into a destination hotel and condominium complex. The only problem was that the city forgot to do any formal environmental impact study. When environmentalists and the state of California sued the city, saying that a "world class airport" and massive condo village would bring unwanted and unsustainable development to the remote area. The judge agreed. His decision forced the Federal Aviation Agency (FAA) to rescind the exclusive, binding hotel development deal.

After the FAA rescinded its prior approval of the grandiose airport expansion plans, the developer sued the City of Mammoth Lakes and won a $43 million judgment. That action caused one of the largest municipal bankruptcies up to that time. If you catch my drift, the political, business and real estate interests in Mammoth Lakes have a long history of obscuring legal, seismic and weather facts, often to suit their own financial needs. In fact, after a $29 million final agreement, the Town of Mammoth Lakes plans to "develop" its way out of the $2 million annual payments agreed to with the spurned airport developer. By continuing to over-develop every possible buildable site in Mammoth Lakes, the city plans to tax its way back to prosperity. Now, even a stay at the local RV Park comes with a daily hotel tax.

Since the founding of Mammoth Lakes in 1877, as a “gold mining town”, the boom and bust cycles of Mono County have been obvious. By 1879, less than two years since the first gold strike, the available gold and silver veins ran out. As usual, those who came late to the gold fever at Mammoth Lakes were left holding useless claims to nonexistent minerals. Thus occurred the first of many real estate busts in Mammoth Lakes history.

Although the area is beautiful, its remoteness puts it at the end of logistical and telecommunications supply lines. Whether from Reno to the North or Los Angeles to the south, one strong seismic event or a massive snowstorm can isolate the city for days, if not weeks. To enjoy an idyllic summer vacation in June, I will happily take my chances at Mammoth Lakes. Even so, living there for more than a few days each year is beyond what I would care to risk, either financially or physically.

Email James McGillis