Death Valley: Wildrose Peak

The deserts of southeastern California and Nevada are expansive, and their large size is driven home by the maze of valleys, canyons, and mountain ranges that add complexity to the landscape. The Panamint Range runs from north to south at the western end of Death Valley. It is a relatively high range, with several peaks over 9000 ft, but it becomes even more prominent in consideration of its position between two low desert valleys to the east (Death Valley) and west (Panamint Valley). In fact, the highest peak of the range is Telescope Peak at over 11,000 ft, which is just miles from the lowest point in North America: Badwater Basin in Death Valley at nearly 300 ft below sea-level.

I set out to Death Valley National Park in late February for a photography project, with just a general concept in mind, and few set destinations. After a first night in the backcountry in northern Panamint Valley and an easy hike to Darwin Falls the following morning, I decided to travel down Emigrant Valley Road, find a campsite at Wildrose campground if available, and continue the drive up Wildrose Canyon. By mid-afternoon I was far up the canyon past the start of the juniper and pinyon pine tree line, and at the start of the trail to Wildrose Peak. I grabbed several cameras and started the hike.

Unfortunately I started too late in the day to make it very far along the trail, but I returned the next morning arriving at the trail head by 7:30. It was cold: 22°F according to my car! Starting up the trail again I passed junipers, pines, and patches of snow. The sun was rising in the east and broke through for a moment, providing some welcome warmth. I climbed towards the east and at an elevation of just under 8000 feet I arrived at a ridge that provided an expansive view of Death Valley to the east. Sunshine was now a regular companion on the trail, and though the air was still cold, it make the hike more enjoyable.

The trail continued to the north and then back to the west, ascending a bit more than another 1000 ft before it would end at Wildrose Peak. Snow patches were common, but in most places they were a thin crust on the cold ground, unlikely to provide much water at all once they melted. The snow may have fallen earlier in the week when California finally – after a remarkably dry January and February – had a winter storm pass through the state. On my drive from Davis through the Central Valley I caught a bit of the storm in Tehachapi Pass where rain, hail, and snow were falling.

The top of Wildrose Peak afforded incredible views of the southwest desert landscape. To the east Death Valley and the Amargosa Range were visible, and Nevada could also be seen including a distant peak with some snow to the east. The lower elevation Panamints were to the north. To the south, Telescope Peak, the highest point of the Panamint range, dominated. Though that mountain was also dotted with dark green evergreens (presumably also junipers and pines), it seemed to have a thicker blanket of snow. To the west was the Panamint Valley and then other mountain ranges, including I’m almost sure, a distant ridge of jagged snow-covered mountains that must have been the eastern edge of the Sierra Nevada.

 

Death Valley to the east

The mountain top at Wildrose Peak had a rock cairn, USGS benchmark, and a metal box with a logbook. A raven was perched at the top of the cairn for sometime before flying off. The mountain top was rather rounded, like the other nearby peaks in the Panamint range. The smoother summit topography perhaps indicates a more ancient origin, with millions of years of erosive forces mellowing the mountains in their old age. While evergreens reached to about the summit of Wildrose, the vegetation was rather low lying and sparse, the species most catching my eye was a prickly pear cactus with long spines, the clusters of stems lying close to the ground and mixed in with snow patches and rocks.

Crest of the Sierra Nevada range to the west

Wheeler Peak to the south

Cairn at the summit of Wildrose Peak

Scoliopus bigelovii

I was out on the northern California coast last weekend for the excellent low tide series. Saturday night I camped at Stillwater Cove Regional Park with the plan to head up to Mendocino County the next day. The clear moonless night gave way to a cool morning and I hiked a bit up the redwood-filled canyon in the park.

Down in the forest understory I noticed pairs of variegated leaves, standing stout like small green vases and eventually found some in flower. The distinctive leaves I’d probably seen before, but I’m not so sure about the even more distinctive flower. It seemed like a new discovery. Back home, a relatively quick look through the lilies in the Jepson manual landed me on Scoliopus bigelovii, a monotypic genus of plants found on the northern California coast (Baldwin et al. 2012). Lilies, including Calochortus, have long been one of my favorite families of plants and now I have found another!

The showy flower has parts of three (indicating a monocot) and appears early in the calendar year according to Jepson and the Marin chapter of the California Native Plant Society. That latter source indicates that the plant’s leaves are still rather small when the flower appears on a long stalk that eventually nods towards the ground when the flower has been pollinated. If you're out on the redwood coast during the early months of the year, see if you can find this beauty!

Stalked jellies

When I was an undergraduate student, I had considerable interest in marine invertebrates, particularly the simpler groups such as the jellies and comb jellies. While I soon turned my attention more to marine algae and later to higher plants, I still find that these simple groups of marine invertebrates are fascinating to behold. They are simple, elegant, and beautiful.

Tidepooling at Trinidad in Humboldt County in late June this summer I found interesting examples of a less common group of these soft bodied, simple invertebrates. I am pretty sure I have not seen these organisms in the field before, but have been aware of them for a while. Classified in the Phylum Cnidaria, this group is known as the Stauromedusae, Staurozoans, or stalked jellies. Cnidaria are comprised of many soft-bodied, often translucent invertebrates that many are familiar with including anemones, corals, and jellyfish. The stalked jellies are sometimes given their own taxonomic class, or order within the class that includes pelagic jellyfish.

The dozen or so animals I found at Trinidad were in shallow pools in the low intertidal zone, each animal only about 2-3 cm in size. They were attached to blades of red algae by an elongated stalk. The other end of the animal broadly flared out like a trumpet and included eight tentacles. Because these animals are very small, perhaps they have been at other sites up and down the Pacific coast I have explored and I have just overlooked them in the past.

I don’t know much about the biology of these organisms, but Dr. Claudia Mills at the University of Washington has a nice summary here. More images of Staurozoans can be seen here.

 

Western climate fires

The extent of the fires sweeping through the west this summer is sobering. As I perused an interactive map published by the New York Times earlier this week, zooming in and out on fire after fire, it dawned on me that several locations I have visited for recreation or traveled through in just this calendar year – in multiple states even – have now burned in the summer fires.

The extent of wildfires in the western US on 15 Sept 2020. Map from InciWeb.

During April, in one of my first hiking excursions since the coronavirus lockdowns began, with my daughter I hiked among and photographed flowers and oaks along the western shore of Lake Berryessa in Northern California. In the LNU fire to tear through that area this summer, most of the western shore of the lake burned. In fact most of the coast range hills down to Interstate 80 between Vacaville and Fairfield have burned.

Oak woodland and blooming lupines during April 2020 on the western shore of Lake Berryessa.

To the east of Lake Berryessa is a hiking location I visit often, the Stebbins Cold Canyon Reserve. It is a teaching and research reserve operated by the University of California, Davis but is open to the public for hiking. Like other places in California was closed for a time due to the coronavirus pandemic. Within a short time of opening back up this summer, I briefly hiked there on a warm day. Signs of a fire several years ago were still evident on the landscape, particularly on the western side of the canyon, but smaller shrubs and smaller plants have recovered. According to the maps though, it appears the whole canyon has burned again.

Also succumbing to the same complex of fires was an area to the northeast of Lake Berryessa, a hiking place I only discovered this spring in my search for more local hiking areas during the pandemic. Valley Vista Regional Park is a small county park located near the scenic Cache Creek and California highway 16 and it features grasslands and lovely oak woodland. This whole area too, it according to the maps has burned.

Oak woodland at Valley Vista county park earlier this year.

The extent of the LNU complex of fires in northern California during summer 2020. Asterisks mark approximate locations I had been hiking at earlier times in 2020. Map from InciWeb.

Finally, on my road trip through Wyoming and Colorado this July, I spent a night camping, and few enjoyable hours hiking in the Roosevelt National Forest north of Rocky Mountain National Park. I hiked into the Comanche Peak Wilderness near the headwaters of the Cache de Poudre River, a lovely valley of aspens and conifers. Virtually the whole wilderness was covered by a large fire.

The Roosevelt National Forest in July 2020. At left: Cache de Poudre River; at right: a grove of aspens. 

The Cameron Peak fire extent in the Roosevelt National Forest. Map from InciWeb.

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We increasingly see signs that climate change is here now. It is not just a phenomenon modeled to occur in the future. While scientists are often reluctant to attribute any specific natural disaster to changing climate, it is becoming more clear with each passing year that we may be entering uncharted territory. In the bigger picture, warming seas are making Atlantic hurricanes more intense. Sea-level rise due to warming and glacier melt is increasing the frequency of nuisance flooding in American cities. And for the last several years in the far western US, the fires have become worse and worse.

The summer fires of 2020 – some call these climate fires – have been everywhere in the western US. In addition to the very places I hiked or photographed or camped in this year, other western landscapes have burned. The beautiful, remote coast of Big Sur: a major fire. The Mendocino National Forest: a massive complex of fires that is still burning. The gorgeous Oregon Cascades: fires so bad they sent air quality levels in Portland and the Willamette Valley to extremely hazardous levels making the region have the worst air quality on Earth for a while. In the Sierra Nevada: several large fires. And northeast of Los Angeles, east of San Diego, and in eastern Washington: more fires.

With each passing year the most pressing question is less about the science and impacts of climate change (although science will always be crucial to monitoring, predicting, and responding to climate change), but rather whether society sees the accelerating pace of change and wants to seriously do something about it. Without reducing carbon inputs into our atmosphere, our future may becoming increasingly uncomfortable, costly, and even deadly.

Burned oak woodland just south of Interstate 80 near Vacaville and Fairfield in northern California. Photo: 16 Sept 2020. 

The Sea of Cortez

Earlier on this blog I wrote about a remarkable field biology course I took as an undergraduate student at UC Santa Cruz where we spent half of the academic term in the northern Gulf of California. Two items lately have moved my mind back to the Gulf.

The first is that I just finished reading John Steinbeck and Ed Rickett’s account of their 1940 expedition from Monterey, California to the Gulf (a long, subtropical sea also known as the Sea of Cortez) with a small crew aboard the Western Flyer. This book was in fact either assigned or optional reading during my UCSC course but I confess that I probably read little, if any, of the book back then.

The route taken by Ricketts and Steinbeck on
the Western Flyer to the Gulf of California.
Image in public domain. Source

Over the course of a six week journey, the biologist Ricketts and his famous writer-friend Steinbeck traveled down the Pacific side of the Baja California Peninsula and northward into the Gulf where they hopped nearly daily from location to location collecting invertebrates during low tide. In addition to describing the fauna they observed, collected, and sometimes aggressively hunted (there is seldom mention of the marine flora, except such brief notes that the mangroves stank), they otherwise pontificate on the science, philosophy, the idiosyncrasies of human nature, and insights gained from various peoples they encountered during their travels.

The second point of convergence is the development of my recent interest in film photography, principally medium format film (but more on that later), which has branched out in a few directions. One trap of the new interest, into which I am not alone in succumbing, is the purchase of more cameras than I probably need, but one of these purchases is at least partly nostalgic as well as functional – a nice specimen of an underwater Nikonos III camera.

The Nikonos series of underwater cameras originated in a collaboration between Jacques Cousteau and a French camera maker. It was called the Calypso originally. The well-known camera manufacturer, Nikon, picked up production of this 35-mm film camera and it became the premier underwater camera line for quite some time. My first use of an underwater camera was in fact a Nikonos camera, also at the time I was a student at UCSC. I shot my first roll or two of underwater film on kelp forest dives in the Monterey area, but as students were also able to use some of these university-owned cameras during our field course in the Gulf of California.

I still have nearly three dozen of the underwater photos I shot in the Sea of Cortez, preserved as color slides. Though not of notable quality, they generally came out better than the surviving slides I first took underwater in Monterey. The Gulf photos show the vibrancy of the marine organisms of the Gulf. Like Ricketts, I was pretty interested in marine invertebrates at the time, and I often aimed the camera on colorful benthic invertebrates of this warm sea.

Various benthic invertebrates from the northern Sea of Cortez. Original: 35mm film, Nikonos camera.

After over a month of collecting, Steinbeck and Ricketts returned up the Pacific coast of Baja back to the central California coast where the Western Flyer would end that chapter of its career as a floating invertebrate laboratory. This boat would go on to fulfill several careers as a fishing and surveying vessel in the North Pacific under a long list of owners, fall into disrepair, and even sink on several occasions in Washington state. In a very interesting story, however, the Western Flyer is on track to return to the service of marine science. After near death, a non-profit group has recently purchased the boat, is exhaustively repairing it in Port Townsend, and plans to return the boat to Monterey and re-trace the 1940 journey by Steinbeck and Ricketts in the year 2022. That year would mark 24 years since I have been to the Gulf; and how fun it would be to arrange a trip to Mexico to see the Western Flyer back in the Sea of Cortez!

The brown alga Padina (Dictyotales). 

Nightpooling

Hawaii has a relatively small tide range compared to the west coast of the US mainland. For example, the spring tide range is less than a meter at Hanalei Bay on the north shore of Kauai. That is much smaller than I am accustomed to in California or the Pacific Northwest where daily fluctuations of the tide can be several meters. However, even with a reduced range, low tide in Hawaii can help reveal interesting intertidal biota on both more wave swept and calmer shores.

Anahola Bay, Kauai with the moon over the horizon.

At the southeast corner of Anahola Bay on the northeast coastline of Kauai, there was significant shelter from the wind that blew in heavy tropical air over most of this coastal enclave during our visit last November. I was exploring the rocks in this calm near sunset and noticed that I had conveniently stumbled upon low tide. As the sun would soon set, I returned to the beach cabin for lights before heading back out to the intertidal. Thus was born my temporary rediscovery of night tidepooling, which I had done only intermittently over the years.

With low tides creeping later with each passing day, I returned to the same corner of Anahola Bay the next evening with the crew. We ambled along the edge of a relatively narrow intertidal of basalt rock inshore of a wide flat reef that was still under some water. Photography in the dark was a new challenge, but not impossible. I held the waterproof camera in one hand, and worked with a headlamp in the other to illuminate organisms from the side where the light would not reflect off the water surface right into the camera.

Our headlamps and lights had a limited reach in the night sky, so my observing eye necessarily focused on organisms immediately in sight. Night brought a sense of being enveloped, like thick coastal fog, where everything beyond the short distance of what was visible would remain a mystery.

Spiny, striped sea cucumber.

Invertebrates and algae on the dark boulders were easiest to observe. Crabs, and large spiny sea cucumbers (echinoderms of the Class Holothuroidea) were common here. I found creeping mats of the green alga Caulerpa and red seaweeds. Much easier to observe during the day, I did see some fish as well. A few brightly colored species swam in the shallows, and in somewhat deeper water offshore, where little light could reach, I observed a few elusive dark, elongated forms. These lurkers may have been large eels.

The lights illuminated tiny dots among the rocks too – the eyes of little shrimp common in the intertidal, shining electric specks.

Night pooling along much of the California or Oregon coastline would probably be rather hazardous at night, especially where large waves frequently crash into the shoreline. But the calm tropics seem particularly well suited for this adventure, and I’ll have to remember this on my next trip to Hawaii!

Napali coast

The Kalalau trail traverses the famous northwestern coast of Kaua’i in what I presume is one of the most scenic hiking trails anywhere in the United States. The first two miles are open to day hikers and a backpacking permit is required to venture further. Because of recent flooding however, the whole trail was closed during our visit to the island last fall.

That unfortunate news left just a few other options to see this dramatic coastline. We availed ourselves of two of these: ridge-top hiking trails accessible from Kokee State Park, and offshore views of the coast from the sea on a chartered boat tour.

The Napali Coast reminds me of Big Sur in central California where in both cases steep coastal mountains abruptly meet the gorgeous Pacific Ocean. The mountains of the Napali coast are more deeply sculpted and luminous than Big Sur, but both are examples of breathtaking coastal wilderness.

Napali coast cliffs from offshore.

Spinner dolphins astride the boat near the Napali coast.

Our first views of this area were by charter boat that left early in the morning from the port on the southern side of the island. A very long sandy beach in southwestern Kauai suddenly gives way to the deeply incised ridges and valleys that rise to several thousand feet above the Pacific. A large pod of spinner dolphins milled around the tour boat, swimming near the bow and leaping out of the water.

We pulled closer to shore at several locations along the Napali coast and anchored at one for a chance to snorkel offshore. The site was in about 10 m of water though I swam in towards shore with my two older kids to a shallower area. Water clarity was decent, though I enjoy swimming in pretty shallow areas when possible because they offer more opportunity to see the small biota on the reef. I was about the last person to hop back on the boat, hoping to spend as much time as possible in the water.

Fishes at our snorkeling spot along the Napali coast.

Our other views of the Napali coast were from above. One must actually circle all around the island from the Kalalau trail, head up the steep road that traverses the west side of Waimea Canyon, and access one of the trails that descends down the mountain ridges from the state parks.

View from the Awaawapuhi trail.

We descended down onto one of the ridges via the Awaawapuhi trail. The coast wasn’t visible at all for the first two miles or so but then the trail ran along a narrow saddle with ravines to the north and south. After another mile and a half it ended, and opened up to a spectacular view of the Pacific from a high point with views to the north and south. A rainbow graced the coastline to the north for a few minutes.

I actually ended up taking a second excursion to the Napali Coast offered by a different tour company. My main interest in this second tour was the destination of Lehua Rock off the north shore of Nihau where the group would be allowed to snorkel. However, before we even departed we were told this might not be possible due to rough seas, and a short time later on the water, that disappointing news was confirmed. We viewed the Napali coast again, but did not even snorkel there, rather stopping at a small cove near the harbor. I now have two excellent excuses to visit Kaua’i again – the Kalalau trail and Lehua Rock!

Small coastal waterfall.

Spinner dolphins.

Rainbow at the end of the Awaawapuhi trail.

Queen Emma's Bath, Kaua'i

(I am still catching up on blog posts from late 2018 and early 2019…the next couple pertain to a trip to Kaua’i in November 2018.)

Fishes in Queen Emma's Bath.

A few years ago, I went with the family to the Big Island, my first visit to Hawaii in many years. Over the course of a week and a half we circumnavigated the island, snorkeling, hiking, and exploring. Three years later during the same fall season, we decided to do a similar trip to the Garden Island, which like the Big Island in 2015, was a new destination for all of us.

One location on the north shore of Kaua’i that piqued my interest before arriving was Queen Emma’s Bath in the Princeville area. This landmark is a large pool set within black basalt at the end of a short trail on a section of coastline exposed to the north Pacific. The first time visited, we were quickly in the thick of a very muddy trail that descends from the parking area to the shore. I was completely unprepared for this sort of hiking, carrying an unwieldy bag and trying to walk on slippery mud in sandals. Once we made it down the slope of red mud and out onto the ledges of basalt, a gorgeous view of the northern shore of the island opened up with the coastlines of Hanalei and Napali in view to the west.

Large swells were crashing on the rocks and made the pool at least a little unsafe for swimming so we just explored the higher rocks along the shore. Water running off the coastal slope created a sort wetland where sedges and other plants grew where sediment collected in the volcanic rock, black tadpoles rested atop the orange silt, and a few light blue damselflies danced about.

Turtles just offshore of Princeville, Kaua'i.

I returned alone to Queen Emma’s two days later better prepared for the trail with sturdier footware and a backpack. However, it had probably had become even worse by this point. Down at the coast the swells had decreased markedly allowing safer access to the intertidal and snorkeling pools.

At the bottom of the trail I first turned east, away from Queen Emma’s Bath, and explored a large shallow pool that I had to myself for the next hour and a half. A ledge of higher basalt protected the pool from the open ocean where waves still hit, but with much less force than a few days before.

Green sea turtles were hanging out offshore of the pool, at times coming right up next to the edge of the basalt ledge. I counted at least five turtles, in a range of sizes. With my phone in hand to photograph them, suddenly a spotted octopus scampered onto the exposed rocks right in front of me! Perhaps its sudden appearance was due to escaping a predator, or it decided to abandon some hiding place because of the turtles swimming nearby. Since my phone was in hand and ready to go, I had the chance to capture a few photographs during the few seconds this normally shy creature was out in the open.

A surprise visit from an octopus!

Near the mouth of the large pool where it connected with the ocean, there were excellent populations of macroalgae. Tufts of bright green Chaetomorpha with individual cells evident to the naked eye were attached to the exposed rocks, and there were carpets of the red alga Pterocladia with its orderly pinnate branching. Other algae thrived submerged in thes shallow pool including the tropical green seaweeds Caulerpa, Halimeda, and Bryposis. I initially mistook one lightly calcified green seaweed, Neomeris, for a benthic invertebrate. There were several species of fish inhabiting the pool, most skittish.

After my more solitary exploration of the first pool, I walked over to Queen Emma’s bath where there was a rather large crowd of people and many were using the pool not for snorkeling, but to jump off the basalt rocks. I snorkeled briefly in the pool anyway, but it didn’t have the best water quality. I then found two smaller undisturbed pools further to the west in which to snorkel. The second of these two smaller pools had lush cover of Sargassum seaweeds and several species of soft corals/ zooanthids. The pools were just large enough for a snorkeler or two and just deep enough to make a bit of a dive under the surface.

One of my small snorkeling pools.

After briefly snorkeling, I explored the exposed intertidal too in this area. It did not disappoint either. There were helmet urchins, Colobocentrotus atratus, pressed to the more wave swept rocks, and underneath a ledge, a small population of tiny red sea grapes, which turned out to be a small species of Botryocladia, one of my favorite genera of red algae!

Botryocladia skotsbergii. 

Blue soft coral Sarcothelia and zoanthid Protopalythoa.

A blenny at the bottom of Queen Emma's Bath.

Cascade Canyon

4 Sept 2018. During my week-long trip to Wyoming last summer, I actually spent more time in Grand Teton National Park than Yellowstone. Prior to visiting, I had heard many positive things about Grant Teton, Yellowstone’s companion to the south. It is smaller, and less crowded than the more iconic park, but certainly had its share of visitors over Labor Day weekend.

Glaciers on the Teton Range.

The Park encompasses a small granitic mountain range with high vertical relief, and is part of the greater Yellowstone ecosystem. The short range runs from south to north and is adjacent to a wide flat valley situated to the east. The dramatic vertical difference between the valley (which lies at about 7000 ft) and the higher of the Teton peaks (which rise to about 14,000 ft) owes it origin to north-south fault activity. Repeated occurrences of large earthquakes led to the uplift of a large block of granite that became the Teton Range.

Deep valleys among the mountains offer some beautiful scenery and opportunity for exploration. Glacial activity has played at least some role in carving out this topography, and there are some small glaciers that are still visible on the eastern side of the range. Glaciers have also presumably contributed to the presence of many of the lakes at the base of the higher mountains. A range of small to large lakes occur at a modest elevation above the valley floor, their water corralled by sills of rock that I assume were pushed out by glacial activity when glaciers were much larger than they are today.

Just south of Grand Teton, there is a deep east-west running valley named Cascade Canyon. Starting near String Lake one morning in early September, MWS and I ventured into the canyon for a 17-20 mile hike that is probably the longest day hike I have ever done.

To ascend up into the canyon there is some elevation gain from String Lake, but once the valley begins to narrow the hike is relatively flat for several miles. The trail on the canyon floor runs along an alpine creek that fans out in some areas, supporting small alpine meadows of Carex sedges or other wetland plants. On the north side of the valley the vegetation becomes more sparse, grading into fields of granitic scree that then slope up even more abruptly into steep granitic walls.

The head of Cascade Canyon near Solitude Lake.

Cascade Canyon is not unlike Yosemite Valley in some days, though the latter has a wider flat valley and more impressive waterfalls. But both present an impressive geologic backdrop to wild nature. After several miles the trail bifurcated to the southwest and northwest and we continued in the latter direction into the head of the canyon. Gaining some additional elevation, trees became sparser and the intense afternoon sun had more of a presence. In the open areas there were more flowers including patches of pink Penstemom blooms. Finally the trail reached 9000 ft to take us to the eastern side of Solitude Lake.

Solitude Lake, Grand Teton National Park.

We returned back through Cascade Canyon because time didn’t really permit the additional climb up into Paintbrush Canyon which would have made a wonderful loop hike. I think I very briefly spotted a fox on our return in the canyon, and an osprey perched on a tall dead tree on the last stretch of our hike back to the trailhead.

Yellowstone's hydrothermals

I haven’t posted on this blog for a year (!) and I have a number of trips to get caught up on, starting with a fun week in Wyoming at Yellowstone and Grand Tetons during late summer of last year.

Hydrothermal feature called "The Fisher"
at the edge of Yellowstone Lake. 

Yellowstone is the oldest national park in the world and I’m sure visitors arrive in this northwest corner of Wyoming for many reasons. For me, the hydrothermal features were the most exciting part of my first visit to this iconic park last summer.

The park’s hydrothermal features owe their existence to a geologic hotspot that lies under Yellowstone. Like the hotspots under the Hawaiian Islands, Iceland, and other locations across the planet, geologic hotspots are places where hot magma rises closer to the Earth’s surface than elsewhere. The volcanic intrusions into the crust heat groundwater that then rises to the land surface in a variety of forms.

One geologic signature of hotspots that I find fascinating is the volcanic traces they leave over the surface of the Earth over geologic time. As the tectonic plates comprising the crust move over the mantle (in the case of Yellowstone it is movement of the North American Plate), the hotspot remains relatively fixed below the moving plates and a “trail” of volcanic activity develops at the land surface over millions of years. This phenomenon is very easily observed with the island chain of Hawaii that formed as the Pacific Plate has gradually moved to the northwest over the Hawaiian hotspot. The trail of evidence is the string of Hawaiian Islands and Emperor seamounts across the north Pacific. In the case of Yellowstone, the history of volcanic activity in that region over the last 15 million years or so can be seen as a series of surface volcanic features that stretches from northwest Wyomingto southeast Oregon.

The Yellowstone caldera and hydrothermal features inside the national park boundaries. Base map from NPS.

Yellowstone has experienced volcanic eruptions a few times over the last several million years, but today volcanic activity in the park is just manifest as earthquakes and numerous hydrothermal features. Four types of hydrothermal phenomena are present in the park. Each is fueled by heat from below the surface, but all involve water at different temperatures and in different quantities. Mud pots consist of little basins of heated mud of different consistencies at the ground surface. The mud inside the pot is formed when acids dissolve rocks. As steam rises through the mud, it gurgles or bubbles at the ground surface. In Yellowstone, I was able to view mud pots at the Artist’s mud pots area southeast of the Grand Canyon of the Yellowstone.

Four types of hydrothermal features at Yellowstone. By CNJ, after NPS display.

Mud plots.

Steam vents, or fumaroles, are a second type of hydrothermal feature. They release super heated water vapor through sub-surface vents. Fumaroles can be small, just quietly releasing a steady stream of steam.

A fumarole near the Artists' Paintpots.

Castle Geyser erupting.

Geysers have subsurface reservoirs that fill with heated water which is periodically ejected violently through an opening in the ground. Geysers can erupt with predictable periodicity or can have irregular timing. Yellowstone has the greatest concentration of geysers anywhere in the world. They are diverse in terms of eruption height and periodicity.

Old Faithful is among the class of regularly-erupting geysers, though it is not the tallest geyser in Yellowstone. It erupts approximately every 70 minutes, and I saw several eruptions during the few days we were in the park. For me, a more impressive geyser was Castle Geyser which only erupts about every 12 hours, but for an impressive 20-30 minutes at a time. I was fortunate to catch one of its episodes. Both Old Faithful and Castle Geyser are in the Upper Geyser Basin where there are a wide variety of interesting hydrothermal features.

Hot springs are the final type of hydrothermal feature. At hot springs, heated water forms pools at the ground surface. They can be rather quiescent or quite active like the Beach Spring which periodically alternates between calm conditions and a vigorous flush of bubbles that rise to the surface of the pool that lasts for a minute or two. 

Examples of hot springs in Biscuit Basin. Shell Spring (left) and Mustard Spring (right).

Hot springs are often lined with precipitated minerals and microbial assemblages, lending them a variety of colors. Blue hues are due to the reflection of other colors of light from the pool. Yellow colors are due to precipitated sulfur compounds. Photosynthetic cyanobacteria and other algae may lend green colors to the water. Bacterial mats at the edges of pools may be white, black, or reddish in color.

Many of the more attractive hot spring pools have two or three colors, but the chromatic display at Yellowstone is most brilliant at Grand Prismatic Spring. This spring is so large it looks like a small lake. Lying across a large flat muddy treeless expanse, steam billows from the superheated spring. When the steam clears, the Grand Prismatic has a beautiful spectrum of blue, green, yellow, and orange.

Grand Prismatic Spring as seen from a trail on the west side of the lake (left) and from up close (right).

Boardwalks facilitate an up-close view of the Grand Prismatic Spring from the east side at ground level, but a short trail that climbs a nearby hillside also leads to a view from above. Since we were backcountry camping for two nights in a forest just a short distance from Grand Prismatic Spring, we viewed it on several occasions and from different angles. In the cool mornings, the brilliant colors of the pool were generally obscured by a large cloud of steam perpetually rising from the spring. However, later in the day as air temperatures warmed, there was less steam to block the rainbow of colors.

Our last of several visits to Grand Prismatic also held an unusual surprise. While we were out on the farthest boardwalk near the edge of the spring, a bison crossed over the boardwalk behind us and into the mudflat to the east of the spring. It seemed unfazed by either the runoff from the spring (which I presume was rather warm), or the eager tourists eyeing the huge animal. In no rush, it seemed unsure of where to go next. We left before learning of the resolution of that event. Curiously I had earlier seen some animal prints in the soil close to the spring, and this surprise visit confirmed that bison do wander quite close to the hydrothermal features from time to time. 

Several examples of smaller springs in Upper Geyser Basin.

The Sapphire Pool in Biscuit Basin.