Mapping Lake Lahontan—with contour lines & color

Landscapes past and present emerge from a surveyor's lines, as if by magic.

In 1881, Israel Cook Russell set out to map a lake that had been gone for 10,000 years, one that had filled the dry basins of northwest Nevada with fresh water. He was eager to survey the great lake, to study its features and learn about its life from beginning to end. And the timing was good! In line with practices of the day, the lake’s story would be told in maps that were artistic as well as utilitarian. 

Russell and several assistants spent three field seasons criss-crossing the immense basin of Lake Lahontan (1). They traversed “broad silent plains of desolation” and rugged mountains “unclothed by vegetation”, often in brutal conditions—hot, dry, no shade to be had. Yet they spared no effort. They surveyed basins past and present, sketching and describing sediments, gravel bars and relic shorelines. All was done in meticulous detail and with great precision (DRHMC).

Rarely did vegetation interfere with line of sight in surveys (ancient Lake Lahontan, now Carson Desert).

"section of Lahontan sediments”; note detail, precision typical of late 19th century scientific illustrations.

Fieldwork ended in the fall of 1883, with a visit by Russell to the far west part of the Lahontan Basin. Just two years later, Geological History of Lake Lahontan: a Quaternary lake of northwestern Nevada (Monograph XI) was issued by the US Government Printing Office (2).

At that time, distribution of GPO publications was governed by law (source). Members of Congress each received a set number, for constituents and institutions in their district. A separate run was ordered by the source of the document, in this case the USGS, to share with colleagues, scientists, other programs and institutions, and international exchange partners.

Surplus copies often were available for purchase, probably at cost-recovery prices (3). I bought a first-edition copy of Monograph XI, issued in 1885, from a rare book dealer for $40—not exactly a cost-recovery price, but reasonable (4). 

When Monograph XI arrived, I was astonished! It measures 9 × 12 inches, weighs 3 pounds 14 ounces, and includes 302 pages of front matter and text with 35 figures, all printed on smooth high-quality wove paper. Forty-five plates on heavier stock, each protected by interleaving tissue, are spread through the book, including 19 maps.

Plate XXXVII: Imitative Tufa forms.

Plate XLVI (excerpt) showing mountains, basins, playas, and an ancient lake.

While Russell and his crew measured, mapped, noted and sketched, chief geographer Henry Gannett was setting up the Survey’s Topographic Branch, including standards and practices for mapping. There were choices to be made, for example between easy-to-interpret hachures and information-rich contour lines.

In the late 1800s cartographers were still debating how to show topography, the shape of the Earth’s surface. What was the best way to create three dimensions on a flat sheet of paper? Europeans generally followed the longstanding tradition of using hachures—short parallel lines, a form of shading. Denser steeper lines were darker, indicating steeper slopes. Map readers found these "terrestrial maps" intuitive. Hachures were considered natural symbols for representing mountains, their locations, and their sinuousities.

Clarence King’s Topographical Map of Central California Together With a Part of Nevada (1873), in hachures.

Hachured mountains from King’s 1873 map; lake upper right is marked with waterlines—parallel lines decreasing in density away from shore.

However, hachured maps lacked precision and even basic information. While they showed location and shape of mountains ranges, distances and especially elevations were little more than suggestions. “They give us only a mutilated image of the land” (source).

Fortunately there was an alternative—contour lines, which connect points of equal elevation. Like hachures they show shape and slope, but with much greater precision.

Where contour lines are closer together, the slope is steeper (USGS 1897, from source).

Contour lines had been around since sometime in the 1700s, but were slow to be widely adopted. Many map users found them confusing. British soldiers are said to have objected, complaining that the lines were difficult to read while hachures were intuitive. Indeed, contour lines are abstract compared to hachures, requiring a greater cognitive leap. But with proper survey, they can provide a wealth of accurate information. 

For Gannett, the decision was easy: the USGS would use contour lines. To assist with transitioning from hachures, early maps often included shaded relief (aka hill shading).

Contour lines with shaded relief (sunlight always comes from the northwest).

Gannett also was forward-thinking with regards to map quality. USGS maps would be printed using lithographic stones, multiple colors, and one of the best color lithography firms in the US.

At that time, most maps were printed directly from metal plates, usually copper. Following the surveyor’s sketched map and data, a skilled engraver cut lines and points into a plate. Copper is suitable for engraving, being relatively soft, but for the same reason, engraved plates became worn with use.

“With great precision, an engraver carefully cuts away small ribbons of copper" (USGS).

“Tools of the trade ... the burin and the hand lens, resting on a contours engraving” (USGS).

The USGS did use copper plates, but NOT to print maps directly. Instead, the engraving was transferred from the plate to a much more durable lithographic stone. The process was complex. Below are step-by-step instructions, in brief (more information here):

• From a surveyor’s sketched map and data, engrave a copper plate.

• Ink the plate and lay a paper sheet on it.

• Press.

• Check print for errors, fix copper plate, make another print, continue until satisfactory.

• Transfer printed map image to lithographic stone using grease pencils, gum arabic and nitric acid (!).

• Ink the stone and lay a paper sheet on it.

• Press.

• Remove paper sheet from plate. Voilá—a map!

Repeat the last three steps for as many copies as are needed UNLESS ... the map has multiple colors. Then one must print EACH map with multiple stones, one per color!

A map "typically required 3 individual lithographic stones for printing, one for each color” (USGS). When the map was moved to the next stone, alignment was critical.

Colors typically used for USGS maps were brown (contour lines and shading), blue (water features) and black (cultural features such as towns and railroads). We see this in Russell’s maps, but with one obvious difference. Two shades of blue were needed, to distinguish lakes past and present.

Today’s small scattered lakes are pale blue; ancient Lake Lahontan is darker; darkest areas are playas (from Plate XLVI).

This complicated process of color printing could not be done in house. Instead, the government contracted with specialists, often Julius Bien & Company. Bien was a pioneer in chromolithography, and his scientific approach to printing made his products exceptional (5). Bien & Company produced many maps for the US government—for Pacific Railroad Surveys, the census, coast surveys, the topographic surveys of the USGS and more.

All color maps in Monograph XI bear the imprint "Julius Bien & Co. Lith."

The more I looked Russell’s monograph and maps, and the more I learned about the cartography and printing involved, the more I wondered … How did a costly science project like this get funded by the federal government, especially during the Gilded Age—a time better known for concentrated wealth, widespread poverty and government corruption.

It was funded thanks to John Wesley Powell, famous for his descent of the Colorado River through the Grand Canyon. He spent his later life in Washington, DC, much of it as Director of the US Geological Survey. Powell knew how to make things happen. He knew the right people, and how to lobby effectively. He even knew the best brand of cigars to hand out as gifts (Worster 2002). And in his requests for funding, he wisely slipped scientific studies—Ice Age lakes and such—in with mandated economic geology projects, chiefly surveys of mining districts. We who love the natural history of the American West are so grateful!

Our hero, with headman Tau-gu, c. 1873 (NPS).

Notes

(1) Russell’s first field season was a solo reconnaissance. During the next two he was assisted at various times by cartographers AL Webster and WD Johnson, and geologists WJ McGee and GM Wright. For more, see "Back to Lake Lahontan ..."

(2) The Government Printing Office is now "Government Publishing Office". 

(3) Sales were overseen by the Superintendent of Documents starting in 1895.

(4) I think I know the reason for the reasonable price. Plate XLVI, said to inhabit the Map Pocket, is missing. In fact, the map pocket on the inside back cover is pristine—perfectly flat and tight, never been used. And at 20 × 32 inches, the map wouldn't fit in that pocket no matter how it was folded. So I downloaded a file from the Rumsey collection and had it printed at the UPS Store.

(5) Julius Bien was a German-Jewish immigrant who fled the failed 1848 revolution. He went on to build one of the preeminent lithography firms in the United States. See Julius Bien, Master Printer and Cartographer for more about this man and his maps.

Sources (in addition to links in post)

Churchill, C. 2025. Variety in hachure. Carl Churchill Blog.

David Rumsey Historical Map Collection (DRHMC). Plate XLVI: Lake Lahontan : a quaternary lake of northwestern Nevada; Media Information. Accessed September 2026. [Many maps in this post are from the wonderful Rumsey collection.]

Edney, M. 2018. USGS printing techniques. Mapping as Process (blog).

Hacker, C. Depicting the Landscape - Part 2. in Cartographic Symbologies, The Art and Design of Expression in Historic Maps. Stanford University Libraries. Accessed September 2026.

NVG. Historical Printing Techniques, Intaglio, in Women’s Work. The Linda Hall. Accessed September 2026.

Raines, A. 2024. Fabricating the World: Copperplate Printing, in WORLDS REVEALED, Geography & Maps at the Library of Congress.

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

Worster, D. 2002. A River Running West, the life of John Wesley Powell. Oxford University Press.

The Monthly Orchid: What do you get when you cross a Coralroot & a wasp?

Answer: Capsules filled with seeds! (Striped Coralroot, Awinch1001)

Welcome back to the The Monthly Orchid, a series about South Dakota's native orchids. This month we again look at Coralroots, specifically the Striped Coralroot, Corallorhiza striata. Coralroots aren't particularly showy, but this one is a bit of an exception. Though the lip petal is small, its stripes are bold. Might they have a purpose? To this, Charles Darwin would reply with an emphatic "Yes!"

Corallorhiza striata; note yellow pollen positioned above base of lip (Freudenstein & Barrett 2026).

Darwin was fascinated by orchid flowers, largely because "the contrivances by which Orchids are fertilised are as varied and almost as perfect as any of the most beautiful adaptations in the animal kingdom." In this diversity, he saw an opportunity to respond to criticism of On the Origin of Species, which he published in 1859.

Just a few years later, Darwin finished another book—The Various Contrivances by which Orchids are Fertilised (1862). In the Introduction, he explained the purpose of his "little treatise" (c. 300 pages):

"Having been blamed for propounding [natural selection] without giving ample facts, for which I had not sufficient space in that work, I wish here to show that I have not spoken without having gone into details."

A myth Darwin intended to debunk was the notion that orchid beauty is "the result of the direct interposition of the Creator" for the pleasure of humans. Wrong! Beautiful orchid flowers are the result of natural selection, and like the vast majority of flowers, they have one purpose—continuation of the species, via sex. 

Why such varied and gorgeous lips? From Kunstformen der Natur, E. Haeckel, 1899.

In last month's post, a Coralroot seed encountered just the right underground fungus, germinated, started to grow, and emerged from the Underworld. We left it surviving on carbon captured by trees and shared (involuntarily) by the fungus. What next? At some point we should see buds, followed by flowers, and then capsules with seeds. Must the fungus help with all this as well? Aside from providing sustenance for growth, the answer is "No". In the case of the Striped Coralroot, however, dependency continues. Now another type of creature will be will be duped.

For most flowing plants (angiosperms), pollination is required to produce seeds. This is what drove evolution of the astonishing diversity in orchid flowers.

South Dakota orchids: Helleborine, Yellow Lady's Slipper, Prairie Fringed Orchid; note the varied contrivances.

With many examples (1), detailed descriptions and lengthy discussion, Darwin was able to argue convincingly that most orchids are designed with insects in mind.

"these contrivances have for their main object the fertilisation of the flowers with pollen brought by insects ... In almost all the species, one of the petals, which is the properly upper one, is larger than the others and stands on the lower side of the flower, where it offers a landing-place for insects, having been carried round by the twisting of the ovarium (2). It is called the lower lip or labellum, and often assumes most singular shapes." (italics mine)

In addition to specialized lips, orchids employ a variety of strategies to lure pollinators (Ackerman et al. 2023; Wikipedia). The most common is attraction by means of reward, e.g., nectar, oil, perfumes. These are given in exchange for pollen transport—arrival from or delivery to another orchid of the same kind. Flower shape, color pattern, and scent are commonly used to attract a specific pollinator, reducing the chance that pollen is wasted on the wrong orchid. 

But many orchids are not so nice. At least a third of the 30,000 known species rely on deception to attract pollinators. Having become highly specialized through natural selection, they are very good at this. Here are some examples.

• An orchid that provides no nourishment has flowers very similar to those of a plant that does. This is feeding deception, the most common type of deceptive pollination. 

• In brood-site deception, an orchid's flowers look like perfect egg-laying sites to the pollinator (see next photo). 

• Even more remarkable is pseudo-antagonism, in which a flower mimics an enemy of the pollinator, invoking an attack during which pollen is transferred!

Cypripedium lichiangense, the Lijiang Cypripedium (Steve Garvie). It offers an appealing (stinky!) but fake brood-site for Ferdinandea cuprea, a hoverfly (Ackerman 2023).

The most fascinating strategy (based on number of studies and websites) appears to be sexual deception, or pseudocopulation. It's the second most common type of deceptive pollination in orchids, documented in at least 22 genera (Ackerman 2023). Perhaps you have already guessed—Striped Coralroot is a sexually deceptive orchid! In fact, it's the first example of a pseudocopulatory orchid from North America!! (Freudenstein & Barrett 2026)

Corallorhiza striata, Andrey Zharkikh.

Freudenstein and Barrett used an insect net to capture wasps visiting Striped Coralroot flowers. They sexed them by looking for a prominent ovipositor. All 28 were male. Another 13 males were captured and sexed in photographs. The researchers then probed 30 of the flowers visited, and found no nectar. 

To determine what was attracting the wasps, they opened a plastic bag of Striped Coralroot flowers inside a net cone, hoping to release volatile scent compounds. Sure enough, within two minutes a swarm of 10 wasps appeared, flew around the cone, and landed on it (they couldn't get to the flowers).

And the stripes? The authors found no obvious resemblance between flowers and female wasps, but the "red stripe down the center [of the lip] flanked by two lighter patches could signal a wasp metasoma" (a body segment). I wonder—how might one test this hypothesis?

Whatever the attraction, all visiting wasps were the same kind—Pimpla pedalis, which is parasitic on the Pale-Winged Gray, a moth that defoliates Eastern Hemlock. In other words, the orchid dupes a wasp that is parasitic on the larvae of a moth that harms trees. Go Coralroot! (3)

If you are unable to view Pimpla pedalis "mating" with Corallorhiza striata (above), go to Freudenstein & Barrett 2026 (open access) and download the video in Supporting Information at the bottom of the page. Or try this video narrated by David Attenborough. It includes neither Striped Coralroot nor Pimpla pedalis, but is quite entertaining!

Now it's time to leave the Coralroots and move on to orchids with morals as well as beauty, perhaps Cypripedium (Lady's Slippers).

"As Orchids are universally acknowledged to rank amongst the most singular and most modified forms in the vegetable kingdom ... examination of their many beautiful contrivances will exalt the whole vegetable kingdom in most persons' estimation." (Darwin 1862, italics mine)

Cypripedium (Darwin 1862).

Notes

(1) Darwin's book includes exotic as well as British orchids. He received many specimens after reaching out to colleagues and collectors.

(2) Darwin is referring to resupination, which is common in orchid flowers. In bud, the lip petal is oriented upward, but by the time the flower opens, the ovary (sometimes the flower stalk) has twisted enough to orient the lip downward. See The Upside Down World of Orchids.

(3) In the orchid's ruse, Freudenstein and Barrett saw the opportunity for an especially alluring title: "Corallorhiza striata is the first example of a pseudocopulatory orchid in North America and an instance of 'double deception' in fully mycoheterotrophic plants." Wow, that's so cool! But wait ... is this really double deception? That depends on your opinion of Coralroots after reading last month's post.


Sources (in addition to links in post)

Ackerman, JD, et al. 2023. Beyond the various contrivances by which orchids are pollinated: global patterns in orchid pollination biology. Botanical Journal of the Linnean Society 202:295–324. https://doi.org/10.1093/botlinnean/boac082 

Britannica. Orchid/natural history/pollination. Accessed August 2026.

Darwin, Charles. 1862 (1904, 7th printing of 2nd edition). The Various Contrivances by Which Orchids Are Fertilised by Insects. London: J. Murray. https://doi.org/10.5962/bhl.title.84436

Freudenstein, JV, and Barrett, CF. 2026. Corallorhiza striata is the first example of a pseudocopulatory orchid in North America and an instance of“double deception” in fully mycoheterotrophic plants. American Journal of Botany 113(4): e70185. https://doi.org/10.1002/ajb2.70185

USDA Forest Service. Coralroot Orchids. The Celebrating Wildflowers—Beauty of It All website is a joy to wander through! I wish I knew whom to credit for it.

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

The Monthly Orchid: Coralroots—parasitic cheats or just slackers?

I walked right by these Coralroots! Fortunately I returned the same way and saw them.

Welcome to the The Monthly Orchid, a series of blog posts about South Dakota orchids. This one features Coralroots, genus Coralloriza—small inconspicuous plants but surprising or even shocking in their ways. After considering their manner of living, you can share your opinion of them in a Comment.

Five Coralroot species grow in South Dakota, all in the Black Hills. But the rest of the state is not nearly as well botanized as the Hills, and these little orchids may be lurking in shady hardwood forests far to the east. I wouldn't be surprised; four of our species occur nearby in Minnesota.

Coralroots are short, slender, drab, and easily overlooked. Stems come in a range of muted colors—red, brown, purple, yellow, occasionally greenish. Color can vary widely among populations of a single species, based on genetics and environmental factors, for example soil acidity.

Kneeling on the forest floor, we see a Coralroot's subtle beauty (Corallorhiza maculata).

Corallorhiza maculata, yellow population (USDA Forest Service).

Yellow Coralroots (Corallorhiza trifida) may be nearly green; but whether they can photosynthesize isn't clear (USDA Forest Service).

Like most orchids, a Coralroot begins life as a seed the size of a speck of dust, housed in a capsule with many thousands of its siblings. When the capsule dries and splits, the seeds are cast to the wind. Being so tiny, orchid seeds have NO endosperm—none of the nutritive tissue that most angiosperms (flowering plants) provide their embryos. So to germinate successfully, they must find help.

With luck, a Coralroot seed lands on a shady moist site with a network of fungal tissue (a mycelium) on or near the soil surface. If the fungus is the right kind—one that can form partnerships with plants (mycorrhizae)—there's a chance that germination will succeed.

Fungal mycelium—a network of hyphae that delivers water and nutrients to whatever is connected to it (Kirill Ignatyev).

When the seed germinates, the tiny embryo develops into a protocorm—a mass of cells less than a millimeter tall just beginning to differentiate. The basal cells allow a strand of fungal tissue to enter, but keep it from spreading further. This is the connection that will nourish the baby orchid. At this point, roots would begin to develop as well, but not in Coralroots. Instead, a short branched rhizome with rounded bumps begins to grow.

Rhizome of Corallorhiza (right) looks like coral, or did to Abraham Gagnebin, who named the genus in 1755 (USDA Forest Service).

Once above ground, most orchids start making their own food via photosynthesis, in tiny green solar-powered food factories in their leaves (and sometimes stems). But Coralroots have no leaves, only bladeless sheaths, and they are rarely green.

Corallorhiza innata (= C. trifida); note short branched rhizome and sheaths on stems (W. Muller 1904).

How do Coralroots survive without roots or leaves? For many years, they were thought to be saprophytic, decomposing and living off organic matter in the soil. Some reputable botany websites still describe them as such. But in fact, they cannot decompose organic matter. Instead, they're part of a complex drama, featuring three very different players.

Most orchids end their fungal dependency after germinating, but a young Coralroot can't. Without photosynthesis it needs a source of food, and will rely on the fungus for the rest of its life. But wait ... fungi don't photosynthesize either! This is where things get complicated.

Tripartate relationship: tiny orchids, fungal network, tree. Note that NO arrows come from the Coralroots.

If we search underground, just beneath the soil surface, we see that the fungal mycelium is linked not only to baby Coralroots, but also to tree roots, in a mutually beneficial relationship. A tree makes carbon compounds via photosynthesis and shares them with the fungus. In return, strands of fungal tissue increase the tree's uptake of water and minerals. Most importantly, the fungus fixes nitrogen in a form the tree can use.

However, while the trees and fungi are helping each other, the Coralroots continue to suck up nutritious carbon compounds from the fungal mycelium. From whence come such compounds? Might they come from dead organic matter decomposed by the fungus? Apparently not. Studies have shown that carbon delivered to the Coralroot by the fungus is produced by photosynthesis, not decay. Trees are the ultimate source.

Knowing this, what are we to think of Coralroots, those delicate little beauties of the forest? They live off carbon produced by trees and delivered by fungi, and contribute nothing in return ... NOTHING! Some botanists call them "heterotrophs" (consumers) that eat fungi. But "parasite" is more widely used and perhaps more accurate, given that they suck nutrients from fungal tissue. And yet no harm to the host has been shown. It's probably best to call Coralroots "mycoheterotrophs"—an awkward but nonjudgemental term specific to their tripartite relationships (Leake 1994).

USDA Forest Service.

What do you think of Coralroots? Do you forgive them their selfish ways? It's tempting to do so, but be aware—they have another dark side, and it has to do with sex! Stay tuned.

Sources (in addition to links in post)

Britannica's mycoheterotrophy article is detailed, interesting and clear. Here's their summary, my insertions in brackets:

"Mycoheterotrophs leach the carbohydrates that the fungi obtained from symbiotic plant partners [trees] and provide no reciprocal benefits. This interaction creates a tripartite relationship involving the autotrophic plant [tree], the fungus, and the mycoheterotrophic plant [Coralroot], with the mycoheterotroph serving as the ultimate sink for the carbon fixed by the autotrophic plant."

Leake, JR. 1994. Tansley Review No. 69. The biology of myco-heterotrophic ('saprophytic') plants. New Phytologist 127:171-216. Free access.

Leake, JR. 2005. Plants parasitic on fungi: unearthing the fungi in myco-heterotrophs and debunking the ‘saprophytic’ plant myth. Free access. 

USDA Forest Service. Celebrating Wildflowers: Coralroot Orchids. This is a wonderful website, offering so much for us to enjoy and learn! I wish I knew whom to credit. Accessed July 2026.