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".
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| Northwest Nevada today. Google Earth, 2021. |
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).
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| 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."
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| "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).
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| 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."
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| "Routes traveled [red 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.
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| 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."
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| "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.
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| 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).
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| 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.
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| Humboldt Lake in Humboldt Sink (Famartin, arrow added). |
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| 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!
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| Gravel quarry below Mopung Hills, east of Carson Sink. |
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| 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.
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| "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.
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| "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.
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| 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).
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| 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.
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| 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
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
Putnam, WC. 1949. Quaternary geology of the June Lake District, California.
GSA Bull. 60:1281–1302.
Russell, IC. 1889. Quaternary History of the Mono Valley, California.
Internet Archive
