Back to Lake Lahontan, with a guy who knows it well

Lake Lahontan (pale gray) is "a large lake which flooded a number of the valleys of northwestern Nevada at a very recent geological date, but now has passed away."

Last May, I visited Lake Lahontan in the company of pioneering geologist Israel Charles Russell. Of course neither was physically present. The lake passed away c. 10,000 years ago, and Russell died in 1906. But Lahontan left behind abundant relics—sediments, shorelines, gravel bars, tufa deposits and more. Guided by Russell's spirit, I was able to "restore in fancy" landscapes very different from today's high desert (quotes are Russell's words unless noted otherwise).

Today's northwest Nevada is a harsh and arid land. "The mountains are rugged and angular, usually unclothed by vegetation. The valleys, even more dreary than the mountains ... form a picture of desolation and solitude." But just 13,000 years ago the basins were flooded, forming "a single irregular water-body" with islands and peninsulas that "bristled with barren and rugged mountain ranges".

Northwest Nevada today. Google Earth, 2021.

Northwest Nevada 13,000 years ago (Matthew Trump).

Israel Russell and I met two years ago in the Mono Basin, in eastern California. He had worked there in the mid 1880s as a geologist with the US Geological Survey. His Quaternary History of the Mono Valley was published as part of the Survey's annual report in 1889.

As well as explaining geology, Russell described with great enthusiasm the beauty, drama and novelty of the landscapes. Citizens of the tiny town of Lee Vining were so taken by his prose that they requested an independent printing of Quaternary History from the USGS, which they would use to entice tourists. It was reprinted in 1984, by Artemisia Press of Lee Vining (still a small town). I found a used copy online.

With Russell's report in hand, I toured volcanoes, relic terraces, glacial features, and Mono Lake—a little lake with no outlet and water so alkaline that one can float on the surface. But it was very different during ice age times, as Russell explained—"a nearly unbroken water surface 28 miles long by 18 miles broad" fed by glacial meltwater, and overflowing to the north. He called it "Lake Mono" to distinguish it from today's relic. Fifty years later it was christened "Lake Russell", a fitting tribute (Putnam 1949).

Lake Mono (now Lake Russell) back when Sierra Nevada glaciers reached the basin (Russell 1889).

About a year ago, I briefly visited the remains of another ice age lake nearby, one contemporaneous with Lake Russell but much larger—Lake Lahontan. When I learned that Russell had studied it too, I immediately made plans to return. From a rare book store, I ordered his monumental Geological History of Lake Lahontan. His words added much to the landscapes I saw—details, highlights, understanding, appreciation.

Russell did not discover Lake Lahontan, nor did he name it. The first to allude to it in a publication may have been John C. Fremont, who crossed this way in 1843 and 1844, and described tufa in his report. But as Russell later wrote,

"... although [Fremont] noted the presence of tufa deposits about Pyramid Lake, and published a sketch of the tufa-coated island ... he does not seem to have recognized that his route led through the desiccated bed of an ancient inland sea."

"Like other rocks along the shore, [the pyramid] seemed to be incrusted with calcareous cement" (Fremont 1845).

Fifteen years later, geologist Henry Engelmann with the 1859 Simpson Expedition very much recognized the ancient inland seas they crossed:

"That the country adjoining Salt Lake and Carson Lake has once been covered with water must strike every observer ... regular 'benches' of shingle and detritus have been formed along the surrounding heights ... They frequently appear as distinct water-marks of equal height all around" (Engelmann 1876; italics mine).

Fort Churchill State Park; note terraces on slope on left—Engelmann's "distinct watermarks".

The first detailed geological study of  Lake Lahontan was done in 1867, by Clarence King, Arnold Hague and SF Emmons as part of the "Geological Exploration of the Fortieth Parallel". It was King who named the "great extinct sheet of water" in honor of Baron de LaHontan, the "gallant French explorer" of the Mississippi headwaters in the late 1600s. However, King's survey was limited to a belt 100 miles wide, leaving large areas of Lahontan to the north and south needing survey and study.

By 1880, King had become Director of the new US Geological Survey, and Grove Karl Gilbert, head of the Great Basin division, had begun his survey of ice age Lake Bonneville in Utah. There he was assisted by a recent hire—Israel Russell. Gilbert was so impressed with Russell's skills and motivation that he gave him his own project—Lake Lahontan in Nevada. In three fields seasons Russell would study and map the entire basin, more than 20,000 square miles, becoming "the first to read [Lahontan's] story, trace its history, and recognize the numerous agencies that varied its life and led to its death."

"Routes traveled [red & pale blue lines] and areas surveyed" (Russell 1885).

Russell started with a solo reconnaissance in 1881. It lasted seven months "during which about 3500 miles were traversed in the saddle." Having crossed the ancient lake multiple times in various directions, Russell was able to decipher much of its history. Details were added during the field seasons that followed, through observation and instrumental work with the help of a topographer and two geological aids. Their studies were extensive, thorough and diverse.

They delineated, measured and made detailed drawings of lakebed sediments. They mapped topography, paying special attention to the geometry of basins flooded by Lahontan's waters. They sampled today's lakes to determine their chemistry and origins. When opportune, they collected fossils and the three types of tufa: lithoid, thinolitic and dendritic. And they measured, mapped, sketched and interpreted relic features left by the ancient lake—beaches, shorelines, gravel bars, spits and more. My hope was to stand where they had stood and see what they had seen, while imagining the waters of an immense lake sparkling in the sun.

See the sparkling lake?

The northeast part of Lake Lahontan lies due west of Laramie, a 770-mile drive on Interstate Highway 80. My first stop was Rye Patch, on the Humboldt River.

"the Humboldt River flows in a channel that it has excavated in Lahontan sediments since the last desiccation of the ancient lake. ... at Rye Patch the river flows a little more than two hundred feet below the general level of the desert. ... Throughout this portion of the cañon the tripartite division of the strata exposed in the steep banks is easily distinguished."

"Lahontan sediments, Humboldt Cañon, near Rye Patch, Nevada" (Russell 1885).

The Humboldt River at Rye Patch was dammed in 1936, but the reservoir was quite low when I visited. From the campground, I viewed Lahontan sediments in the canyon walls just above the water, with a typical "angular unclothed" range rising above.

Lahontan sediments, Humboldt Cañon, near Rye Patch, Nevada, 2026.

I saw what looked like the "tripartate division" described by Russell (click on image above): pale clays at the base, which settled when the lake was deep; then a darker bed of gravel washed in when the lake was shallow and much smaller; and on top, more clays when it again filled. These three layers were important evidence for Russell's conclusion that "two high-water stages [were] separated by a time of desiccation" (still widely accepted).

Detailed section showing Lahontan sediments near Rye Patch (Russell 1885).

The next day I awoke to rain. So I toured Lake Lahontan by van searching for relic features. From Rye Patch I drove west and then south on I-80, following the Humboldt River to where it ceases to exist, the last of its trickles having sunk into the Carson Desert (as do the Carson and Truckee Rivers nearby).

I drove for miles across "broad silent plains of desolation" while thinking of Russell and his crew working in the heat of summer, without shade, and with no water except for the rare pool in a playa. That was too alkaline to drink of course, but as their tests showed, it also was too fresh—not salty enough to be the last remnants of Lahontan. The great lake must have evaporated entirely.

Humboldt Lake in Humboldt Sink (Famartin, arrow added).

Playa up close: "tessellated pavements of cream-colored marble"

When the rain let up, I decided to look at gravel. Being a highly irregular lake occupying multiple basins connected by narrow straits, Lahontan left behind a lot!

"Accumulations of gravel in the form of bars and embankments occur at many points along the ancient shores ... These are seldom straight, but curve with beautiful symmetry, each gracefully bending ridge marking the course of a current in the waters of the ancient lake in which it was formed."

Out of convenience, I stopped at a quarry. No gracefully bending ridges were visible, but I enjoyed wandering around and contemplating the handiwork of Lahontan's currents. And the size of the deposit was astonishing!

Gravel quarry below Mopung Hills, east of Carson Sink.

Immense gravel bar, shaped by quarrying.

The next day I awoke to sunshine, and again departed Rye Patch on I-80. After crossing the subtle divide between Humboldt and Carson Sinks, I turned south on US Highway 95. My destination was Russell Pass on the shore of Lake Lahontan, at the south end of the Carson Basin. It's clearly marked in Roadside Geology of Nevada (DeCourten & Biggar 2017) and on the local USGS topographic map. There I would commune with Russell's spirit and view the lake phenomena he described.

About 18 miles south of Fallon, a notch came into view. Everything looked right—bold rugged volcanic rocks, some encrusted with tufa, and slopes girdled with terraces. But at the pass was an unexpected sign, and no place to pull off.

"ENTERING Gabbs Valley Watershed"

I continued south a short distance to the Russell Pass Landfill, where I checked several maps. Indeed, Russell Pass is on the divide between the Carson and Gabbs Watersheds. Confident I had visited Russell Pass, I turned around and began my search for Russell Spit.

When Lake Lahontan was full, the pass and adjacent highlands were an island. On one side was a narrow strait "through which the currents must have swept with great force" given the impressive group of gravel bars and spits that formed.

"Gravel embankments on south border of the Carson Desert, Nevada" [arrow mine].

Plate XIX above, by topographer WD Johnson, was one of the more exceptional illustrations in Russell's Monograph. Roger Morrison included it verbatim in his report on the southern Carson Desert (1964). By that time, the gracefully curving gravel bar (white arrow) east of the large playa was known as "Russell Spit" but exactly when the pass and spit were named appears to be lost (I'm still searching). It must have been before 1951, when the Russell Spit 7.5' topographic map was first published.

From the highway, I turned off at a sign for the Top Gun Drag Strip, where races were underway (audibly obvious). On excellent gravel roads I explored as far south as a huge gravel quarry, where I concluded I didn't know what to look for. Or could Russell Spit be gone? I turned around.

Volcanic rock and tufa, with gravel everywhere.

I stopped to examine pinnacles of volcanic rock and large blobs of tufa. Based on what I read and saw in the Monograph, it looked like dendritic tufa, "by far the most abundant of all the chemical deposits of Lake Lahontan."

"Dendritic tufa deposited on a cliff" (Russell 1885).

Dendritic tufa near Russell Pass, 2026.

Then I looked east across the highway and spotted the terraces Russell saw when he was here, horizontally scored in soft volcanic rock.

Ancient shorelines—"the most common of the records inscribed".

With that, my search for Russell Spit came to an end—unfulfilled perhaps, but hardly disappointing. I had stood where Russell stood, experienced the gravel he had experienced, gazed on tufa-coated volcanic rocks and wave-cut terraces as he had, all the while "restoring in fancy" Lake Lahontan sparkling in the sun.

Sources

David Rumsey Map Collection. Geological History of Lake Lahontan, maps and illustrations.

DeCourten, F, and Biggar, N. 2017. Roadside Geology of Nevada. Mountain Press.

Engelmann, H. 1876. Geological report of country from Fort Leavenworth to the Sierra Nevada, pages 247–336 in Simpson, JH, et al. Report of explorations across the Great Basin of the territory of Utah : for a direct wagon-route from Camp Floyd to Genoa in Carson Valley in 1859. BHL

Fremont, JC. 1845. Report of the exploring expedition to the Rocky Mountains in the year 1842, and to Oregon and north California in the years 1843-'44. Internet Archive

Morrison, RB. 1964. Lake Lahontan: geology of southern Carson Desert, Nevada. USGS Prof. Paper 401.

Putnam, WC. 1949. Quaternary geology of the June Lake District, California. GSA Bull. 60:1281–1302.

Russell, IC. 1885. Geological history of Lake Lahontan. USGS Monograph 11.

Russell, IC. 1889. Quaternary History of the Mono Valley, California. Internet Archive

By the Shores of Lake Lahontan

Camping on a different kind of beach.

Beachcombing through tufa, not sand.

Last fall, on my way home from California, I drove through northwest Nevada intending to make several brief geostops on the shores of Lake Lahontan. But it was so interesting and so curious that I stayed over two nights. By doing so, I was able to follow in the footsteps of one of the great pioneering geologists of the American West—Israel C. Russell.

I met Russell several years ago in the Mono Basin, not far west of Lake Lahontan. Guided by his spirit, I toured the basin seeing landscapes through his eyes and his words (Russell 1889). He was a terrific writer, and that was a time when geologists weren't constrained by today's conventions of scientific writing. It was wonderful to share his awe and appreciation for the novel geologic features he found.

Israel Russell (source). "his physique gave to the eye little suggestion of that capacity for sustained effort and endurance without which his more strenuous exploration would have been impossible." (Gilbert 1906)

In 1880, Russell joined Senior Geologist Grove Karl Gilbert of the US Geological Survey in a study of what were thought to be relic shorelines, across a huge area in western Utah. Impressed with Russell's diligence and field skills, Gilbert gave him his own project—a survey of similar features to the west in Nevada It would commence the following year.

During the first field season, Russell made a geological reconnaissance "during which about 3500 miles were traversed in the saddle" (all quotes his unless noted]. That winter he prepared a "Sketch" of his findings, starting with a description of the region—expansive, harsh, unusual in the extreme, and "standing in marked contrast in nearly all its scenic features with the remaining portions of the United States."

"The traveler in this region is no longer surrounded by the open, grassy parks and heavily-timbered mountains of the Pacific slope, or by the rounded and flowing outlines of the forest-crowned Appalachians, and the scenery suggests naught of the boundless plains east of the Rocky Mountains or of the rich savannas of te Gulf States. He must compare it rather to the parched and desert areas of Arabia and the shores of the Dead Sea and the Caspian."

Though unlikely to attract "the pleasure-seeker", the region offered a "peculiar fascination" to geologists, for two reasons. First, "the absence of vegetation gives such unusual facilities for investigation". Often not a single tree can be seen for hundreds of miles, and only the rare robust sagebrush offers any hope of shade. Rock and soil are well-exposed.

The barren range beyond the playa was one of Lahontan's many islands and peninsulas.

Second, "the character of the problems to be solved" was irresistible. This was an area rich in geologic novelties, Lake Lahontan being a fine example. Water is scarce to non-existent, and more than a few travelers have chased mirages, gagged on alkaline muck, and perished from thirst. Yet a host of scattered shorelines, tufa deposits, and gravel bars suggest Lahontan was once a huge freshwater lake sparkling in the sun.

Lake Lahontan in its prime, just 13,000 years ago (source).

Routes traveled [red lines] & areas surveyed (Russell 1885); source.

Russell and various assistants would spend two field seasons studying and measuring Lake Lahontan. They determined the elevations of basins (the old lake bed) and terraces on the slopes above (shorelines). They sketched ancient gravel bars and sand spits, and collected samples of the various types of tufa. And they surveyed and mapped nearly 8500 square miles. The result was monumental: Geological History of Lake Lahontan, a Quaternary Lake of northwestern Nevada; Monograph 11 of the US Geological Survey.

"Depth of Lake Lahontan at highest water stage" (excerpt, note depth measurements); source.

"A characteristic specimen of thinolite" [a controversial type of tufa]; source.

From "Map of Lake Lahontan" (c. 20 x 32 inches in its entirety). Note shaded relief overlying contour lines—subject of a future post.

During my visit last year, I toured a northern arm of Lake Lahontan—today's Black Rock Desert and "Lake" Winnemucca to the south.

Black Rock Desert playa is open to driving, fireworks, camping & more (I stayed on the shoreline above). 

From the Black Rock Desert, I drove south along today's Lake Winnemucca, and stopped at a large tufa tower next to the highway. Tufa is sometimes described as a porous limestone; it forms where freshwater meets carbon-dioxide-rich waters, such as springs, streams, and lakes. In his monograph, Russell described three types and partially clarified an "embarrassing" earlier hypothesis for thinolite.

Tufa tower along NV Hwy 447.

Tufa up close.

Lake Lahontan shorelines above today's mostly-dry Lake Winnemucca.

With that stop my visit to Lake Lahotan came to an end. It was much too brief, and I left determined to return.

"The bare mountains reveal their structure almost at a glance, and show distinctly the many varying tints of their naked rocks."

Sources

Gilbert, GK. 1906. Israel Cook Russell. J. of Geology 14:663-667.

Russell, IC. 1885. Geological History of Lake Lahontan, a Quaternary Lake of northwestern Nevada; Monograph 11 of the US Geological Survey.

Russell, IC. 1889. Quaternary history of Mono Valley, California (in USGS 8th annual report). Russell's report was reprinted in 1984 by Artemisia Press, Lee Vining, CA.

White Mountain in the Black Rock Desert

Gypsum as sand.

If you've read my recent posts (1), you know that in May I visited Utah’s Black Rock Desert volcanic field. But volcanics weren’t the only attraction. Lake Bonneville was just as obvious, fascinating and demanding of attention. As recently as 15,000 years ago, this Ice Age lake covered much of western Utah. Now thick beds of sediments obscure volcanic evidence, and brilliant white playas—Bonneville’s desiccated remains—flash in the sunlight. One afternoon we visited a special playa near the south end of the old lake. It’s made of gypsum, and the rhyolite dome at the north end is nearly buried in gypsum sand.

Gypsum (calcium sulfate dihydrate, CaSO₄·2H₂O) is a common mineral generally found in evaporite beds associated with sedimentary rocks. Where it occurs in large quantities, it’s mined (2). It’s used mainly for plaster and drywall (aka sheet rock, wallboard), as well as other less common but important applications.

Gypsum forms through evaporation, crystallizing out of increasingly concentrated solutions. Therefore it dissolves easily in water, and rarely lasts long enough to form sand. The most notable exception is the 700 sq km White Sands dunefield in New Mexico, the largest accumulation of gypsum sand in the world. It’s said to contain enough gypsum to meet global drywall demand for the next thousand years. Fortunately commercial exploitation was nipped in the bud in 1933, when President Herbert Hoover designated the dunes a national monument.

Google Earth view of White Sands National Monument, New Mexico; note scale.

Then there’s the White Mountain dunefield five miles west-northwest of Meadow, Utah. It covers only 0.1 sq km, so there’s little risk of commercial development, though a great geologist—the first to describe the area—noted:

“Perhaps no gypsum deposit in the world is so easily exploited as this; it needs merely to be shoveled into wagons and hauled away.” GK Gilbert, 1890

Google Earth view of White Mountain in the Black Rock Desert, Utah; note scale.

The White Mountain dunefield is tiny, but there’s enough of interest to justify a stop. And there’s little to interrupt ones reverie. On a warm day midweek in May, the only visitors were myself, my dog and the spirit of Grove Karl Gilbert, my favorite pioneering geologist.

GK Gilbert, “one of the greatest American geologists of the 19th century—a man who should be ranked with Lyell, Agassiz, and Smith” (National Academy of Sciences Archives photo, from Picard 2008).

From 1871 to 1879, Gilbert served as geologist on two of the Great Surveys of the American West, working for both Lt. George Wheeler and John Wesley Powell. He loved field work, in spite of (or maybe because of) the rigors of western exploration (3). He had a sharp and creative mind, and his contributions to geology are legendary, for example discovery of laccoliths, comprehensive description and mapping of Ice Age lakes, and development of some of the most basic concepts in geomorphology.

Lake Bonneville (Gilbert 1890); added circle and arrow mark Sevier Body and White Mountain.

Gilbert spent much of his field time in western Utah and adjacent Nevada, ostensibly gathering practical information such as location of irrigable lands. But he also studied and mapped playas, relic shorelines and other features of Lake Bonneville—the basis for his great 1890 monograph. Near the southern end of the Sevier Body, he discovered a playa that “differs from all the others in that its material is gypsum.”

“It was ascertained by digging in the playa that a portion of the deposit is amorphous and another portion crystalline. One phase of the precipitation results in the formation of small free crystals, which the wind sweeps from the surface of the playa and gathers in dunes. The dunes do not travel to a great distance, but are arrested by a low rhyolitic butte near by, to which they have given the name of White Mountain.”

Partial map, from Gilbert’s 1890 Lake Bonneville monograph.

The map above shows the southern part of the “Volcanic District near Fillmore, Utah” (today’s Black Rock Desert) with the playa of gypsiferous clay (GC, pale yellow) and crystalline gypsum (G, horizontal hatching). At the north end is White Mountain—rhyolite (R, red dots) and accumulations of gypsum sand (GS, vertical hatching).

Trail to top.

White sand verbena, Abronia elliptica.

Unknown travelers.

White Mountain is underpinned by a “small” rhyolite dome that erupted about 400,000 years ago. Its actual size is unknown due to overlying Lake Bonneville sediments and basalt flows. The White Mountain rhyolite may be significantly more extensive below the surface, as blocks have been found in the Tabernacle volcanic field to the west, active just 12,000 years ago (Johnsen 2010).

View from White Mountain summit: lava flow and cinder cone, with Pavant Butte behind.

Enjoying a bit of shade provided by White Mountain rhyolite.

Closer view, note layering … ??

Of course one wonders why Lake Bonneville would leave behind only a single gypsiferous playa. In his monograph, Gilbert attributed its uniqueness to nothing more than location—downstream from gypsum-containing rocks:

“It is probable that the deposit is independent of any special chemical reaction, and is due simply to the discharge by evaporation of a mineral dissolved from the rocks. The streams whose waters occasionally flood the playa rise among strata of Jurassic and Triassic age, and such strata in a neighboring mountain range are known to be highly gypsiferous.”

Grove Karl Gilbert c. 1910; USGS photo.

In my readings for this post, I learned that sometime before 1906, Gilbert met and fell in love with the great California botanist Alice Eastwood, probably on a Sierra Club outing. Plants and rocks—a wonderful match! In 1917, after a decade of "courtship," they made plans to marry the next year. Sadly, Gilbert died on May 1, 1918.

Alice Eastwood next to “rift” from the 1906 San Francisco earthquake (Marin County, GK Gilbert photo; Archives of the California Academy of Sciences, see Aldrich et al. 2006).

Notes

(1) Previous Black Rock Desert posts include Volcanoes in Utah—how can that be?!, Sunstones at Sunstone Knoll and A Caldera Lake?

(2) Flue-Gas Desulfurization (FGD) gypsum now equals natural (mined) gypsum in wallboard manufacturing. FGD gypsum production utilizes emissions captured from fossil-fuel power plants. The product is chemically identical to natural gypsum, but with higher purity (more here).

(3) Ironically, Gilbert was a sickly child, and even at 20 was frail enough to be passed over in the Civil War draft. Apparently field work changed him dramatically.

Sources

Aldrich, ML, Leviton, AE, and Elsbernd, K. 2006. Grove Karl Gilbert’s photographs as evidence in geology: Documenting the 1906 San Francisco earthquake. PDF

Gilbert, GK. 1890. Lake Bonneville. Monographs of the US Geological Survey, v. 1. Available here.

Jenkins, MC. 2018 (January 8). Grove Karl Gilbert, ‘A Captain Bold’ National Geographic blog.

Johnsen, R, et al. 2010. Subalkaline volcanism in the Black Rock Desert and Markagunt Plateau volcanic fields, in Carney, SM, et al., eds., Geology of south-central Utah. Utah Geological Association Publication 39.

Picard, MD. 2008. Grove Karl Gilbert, master of laccoliths and lakes, in Profiles of Rocky Mountain geologists, a continuing series. Rocky Mountain Geology 43:111-118.

Sepp, Siim (Sandatlas). 2015. Gypsum sand.