Jack Frost and Aeolus – Partners in Art

On the crest of the Medicine Bow Mountains, just 50 miles west of Laramie, Wyoming, stands the Snowy Range—a sharp-edged thousand-foot-high six-mile-long ridge of quartzite that glistens in the sun. Trails run along its base, cross it at the Gap, and climb to various points along the summit, including Medicine Bow Peak, the high point at 12,014 ft. Though the trailheads are in the subalpine zone, they're just an hour’s drive from town, making the high country surprisingly accessible. And the scenery remains spectacularly photogenic, even after thirty years of hiking there.

But with hundreds of photos of “the Range” already, do I really need to carry a camera? This is one of life’s persistent questions. Fortunately, I can still convince myself there’s a chance of finding something new, fascinating, or at least entertaining.

Emmie's first visit to the Snowy Range.

Contemplating the final push to the summit of Medicine Bow Peak, just out of view on right.

The Snowy Range is a very popular hiking area in the summer, but my favorite time to visit is early fall, especially on weekdays. Temps are cool, and the lower light makes for richer scenery. Usage is low, parking is no problem, and well-mannered dogs can hike off leash.

Looking back toward trailhead at Lewis Lake, below Sugarloaf (on right).

Last Thursday we hiked one of the most popular trails in the Snowy Range, the short but nontrivial jaunt from Lewis Lake up to the Gap Lakes. There were just four cars in the parking lot, and two people along the trail, enjoying lunch at the Gap. The only other creatures seen were a marmot, a chipmunk, two pikas and a seagull. It was a quiet fall day aside from the wind, which wasn't bad.

From North Gap Lake, a short trail east led to the Shelf Lakes—small shallow sparkling lakes below immense piles of quartzite talus. It was here that I was happy to have brought the camera.

View west from Shelf Lakes; Medicine Bow Peak is bump at left end of ridge, above and right of snowfield.

From a distance, I saw that the far end of the first lake was rimmed with white, looking like salt along the shore of an alkaline lake, as we would see down in the Laramie Basin.

Note white line along vegetated lakeshore mid photo (not rocks on right).

But it wasn't salt. Each of the Shelf Lakes was lined with ice sculptures at the east end—which happened to be the downwind end. Apparently it was cold and windy enough recently for waves breaking against the shore to build up ice on plants and rocks.

We spent about an hour admiring the artwork, and then ate lunch by one of the lakes, sitting next to the downwind side of a giant boulder.

Botany geeks—if you look closely (click on images below), you can see that the graminoids encased in ice are mostly sedges (Carex), not grasses.

The branchlets of low shrubby willows (Salix) were strong enough to support long artistic drips. And with their stems encased in ice, a few willows appeared to be dancing.

As always, Jack Frost disappeared after creating his sculptures, so I was left to speculate as to the process. However, his hypothesized collaborator, Aeolus, was still very much present—whispering, whining, and even howling a bit, as he stirred up eastbound wavelets on the lakes and confirmed my theory, at least in part.

Click on image to see a few tiny white caps in the distance (shallow lake).

Belly Willows

Being a fan of NPR’s A Way with Words, I was pleased to discover that the July 10, 2017 program included belly flower! As Martha Barnette explained, “it’s a term for a small low-growing wildflower, the kind that you have to get down on your belly to see.”

But I already knew this. I was looking for a term for belly flowers no longer in flower—instead with fruits or seeds. I didn't have much luck. Because “belly fruit” and “belly seeds” sounded too much like New Age remedies, and “belly plant” was already in use, I decided on “belly willow”.

Belly willows are my favorite willows, mainly because they grow in spectacular settings high in the mountains (they're also easy to identify). Arctic Willow, Salix arctica, is common in the Medicine Bow Mountains just 50 miles west of town. Plants are typically just a few inches tall, forming a low cover of leaves above stems winding along the ground. Being a belly willow, Arctic Willow is wonderful to stumble upon if one is used to willows as trees or shrubs—a really fun discovery: “Oh my, willow catkins and leaves at ground level!”

Male flowers of Arctic Willow (like all willows, it’s dioecious). Matt Lavin photo (cropped).

Arctic Willow in fruit (specifically capsules). Andrey Zharkikh photo (cropped).

True to it’s name, Arctic Willow is common and widespread in the Arctic. But it also occurs further south at high elevations, for example in the Sierra Nevada of California, and in the Rocky Mountains as far as New Mexico. Adapted to short seasons, it grows slowly and is long-lived (one individual in Greenland was determined to be 236 years old).

Late-season meadow at base of Snowy Range, crest of Medicine Bow Mts., Wyoming.

Last week I was sprawled belly-down at 10,500 feet above sea level in a “wet” meadow (now dry) in the Medicine Bow Mountains, communing with Arctic Willows. Autumn had arrived—their leaves were a mix of green, yellow, orange and red. Only a few plants still had intact capsules; most had split open to release their seeds. Scattered across the meadow were wads of fluff embedded with tiny willow seeds, waiting for wind.

Each tiny willow seed has a tuft of fine cottony hairs for flying with the wind (American nickel for scale, about 2 cm across).

Dried split capsules stay on the plants after releasing seeds. They're visible in the wad of seed hairs below.

Of course most of our willow species sent their seeds off long ago, in late spring or early summer. But snow melts late at 10,500 feet—the season is short, and plant phenology is compressed. The  belly willows in this meadow had only about two months to go from flower to fruit to seed.

“gentians don't mind the first frost …”

Late summer on upper Deep Creek; Medicine Bow Mountains, Wyoming.

The wet meadow along Deep Creek was mostly dry. I walked through tall grasses and sedges topped with brown seed heads, their leaves turning yellow, and low shrubby willows with lusterless-green upturned leaves. But my feet stayed dry. Tiny ponds and mud holes were the only surface moisture. This is typical for September in the higher mountains.

Short field assistant deals with tall sedges and grasses.

What caught me by surprise were all the rich blue patches of life scattered about—a beautiful contrast!

But I shouldn't have been surprised. Pleated Gentians (Gentiana affinis) are always late bloomers. Yet I was caught off guard. It’s not that they were unexpected; they just aren’t part of the seasonal picture until I’m reminded.

Pleated Gentian, Gentiana affinis. Both flowers and buds were common. 

Gentiana is a large cosmopolitan genus, with on the order of 400 species. Most are native to the Northern Hemisphere. Many grow in montane to alpine habitats, where mountaineers love them for their showy displays on harsh sites, and their proclivity for blooming even as summer winds down.

Arctic or Whitish Gentian, Gentiana algida, “common to alpine settings in the Rocky Mountains.”

Matt Lavin photo.

The Pleated Gentian is widespread in western North America, in moist habitats ranging from montane to alpine. Other common names include Trapper’s Gentian and Marsh Gentian (and there are probably more).

It’s odd that this gentian is designated "Pleated".  True, it does have folds or pleats between the petal lobes. But then so do all true gentians—members of the genus Gentiana (for example the Alpine Gentian above). The botanical term for this flower form is “plicate” meaning folded, like the pleats of a curtain.

Larger blue lobes are petal tips; smaller ones in-between are pleats.

Ragged tips of pleats show nicely in photo of Gentiana affinis by Rolf Englestrand [cropped].

When I first tried to identify this gentian, the flowers led me astray. I assumed that the dull green covering of the buds, which “persists” when the flower opens, was sepals—the outermost whorl of flower parts, usually green. But no … that green tissue is part of the petals. The sepals are indeed green, but they’re tiny and hidden under leaf-like bracts.

Pleated Gentian flower bud; just the green petal tissue is visible (see flower parts below).

Gentians were a favorite of the great mountaineer, naturalist and conservationist, John Muir. He often mentioned them in descriptions of mountain meadows in the Sierra Nevada of California. Muir especially appreciated their habit of blooming so late in the season, providing much-welcomed color.

“The gentians don't mind the first frost though their petals seem so delicate; they close every night as if going to sleep, and awake fresh as ever in the morning sun-glory.” from My First Summer in the Sierra (Chapter 10)

Communicating Earth Science: Stromatolite Stroll

Stromatolites showing off their arched layers.

As I mentioned a few posts back, I’ve been writing geology/history articles for our local paper, the Laramie Boomerang. Finding topics is easy; there’s no shortage of interesting features nearby. And telling their stories to the general public is doable and rewarding—if done right. But that’s the challenge.

The most recent article (below) was especially difficult, for it was about stromatolites. Ours are some of the most spectacular in the world, yet few locals know what a stromatolite is—much less that we have famous ones nearby. Adding to the challenge, their story is long, two billion years in fact. Finally, the Boomerang guarantees publication of only one photo!! This is a serious obstacle in explaining Earth Science, where a picture is indeed worth a thousand words. So I’ve added a few more for this post, including the cartoon at the head.

Most importantly, a many many thanks to Professor Emeritus and stromatolite expert Don Boyd! Don reviewed and edited my draft under most adverse conditions. First, the deadline was bumped up by a month, giving us only ten days for review and revision. Then the day after receiving the draft, Don broke his hip. That was Tuesday. On Thursday, he had it replaced. Physical therapy started Monday. But he continued editing, and we made the Wednesday deadline with a half day to spare. Don has a reputation for “being tough” and he certainly lived up to it (I suppose I should mention that he’s 92). His determination to stay active, physically and mentally, has made him a terrific role model for me!

Our Spectacular Stromatolites (Say what??)

by Hollis Marriott, Contributing History Columnist

Laramie Boomerang, September 1, 2019—“Laramie’s Living History”

“Big Daddy”—a humongous stromatolite now visible in cross-section, having been planed and polished by glacial ice. Medicine Bow Mountains, Wyoming.

High in the Medicine Bow Mountains west of Laramie, near the base of the Snowy Range, lie spectacular finely-layered rounded rock structures reminiscent of cabbage. These are stromatolites—in fact, some of the most spectacular stromatolites on Earth. They’re two billion years old, are now more than 10,000 feet above where they formed (sea level), and in some cases are true monsters (15+ ft. across!). Actually, we’re doubly lucky. Not only do we have world-famous stromatolites, there’s also a free guidebook that will lead us to the finest examples.

This is why “stromatolite” should be part of our vocabulary. The word is easy to say: “stroe MAT toe light.” And its Greek roots are appropriate: “stroma” means layer, “lithos” means rock. Stromatolites consist of thin layers of sediment cemented with calcium carbonate (the mineral that comprises seashells)—and thereby turned to rock.

It was geologist Ernst Kalkowsky who coined the term in 1908, for some unusual rock structures he discovered in the Harz Mountains of Germany. “The new term ‘Stromatolite’ is proposed for limestones with unique organization and structures … a fine, more or less even layered fabric,” he wrote. Furthermore the thin layers were arched, forming domes and mounds (usually sediments are deposited in horizontal layers). Kalkowsky suggested that stromatolites were biological—made by primitive organisms.

OUR “ALGAL (?) DOMES”

In the summer of 1917, geologist Eliot Blackwelder, then at the University of Illinois, and a student assistant, spent six weeks in the Medicine Bow Mountains studying the ancient, Precambrian rocks of the high central part. A young local geologist, S.H. Knight, son of Wyoming state geologist, Wilber C. Knight, joined them for part of the season. Blackwelder noted that though the Knights had visited the range on multiple occasions, “no detailed work seems to have been attempted and the results of such examinations do not appear to have been published.” That would change, but only after fifty years had passed.

After more fieldwork in 1925, Blackwelder prepared what would become a classic paper on the Precambrian geology of the Medicine Bow Mountains, published in 1926. He devoted two pages to what he considered some of the most interesting features in the range:

“There are many concentric domes, or globes, crowded together and all resting on a common base. These domes range in size from an inch or more to as much as 10 feet in radius. Their gross anatomy is generally emphasized by alternations of [dark and light layers], of which the latter weather out in relief. A close study of these features strongly suggests that they have been built by colonial organisms, such as calcareous algae.”

"Large dome-shaped structures" from Blackwelder's 1926 report (also in photo at end of post).

Blackwelder sent photographs, including the one above, to esteemed paleontologist Charles Walcott of the Smithsonian Institution, who concluded that the odd structures were biological, probably of algal origin. But in the absence of hard evidence, Blackwelder called them “algal (?) domes” in his paper.

His caution was understandable. In Blackwelder’s day and for decades after, it was thought that stromatolites had disappeared long ago, after organisms evolved that ate the algal builders. Therefore any explanation would have to be speculative. Though common as fossils, no modern-day stromatolites were available to illustrate how the ancient ones formed.

WRONG!

In 1956, oil company employees stumbled upon an odd sight on the west coast of Australia. In the warm super-salty water of a shallow bay stood many finely layered rock domes about three feet tall—“living” stromatolites! More have been found since then, usually in extreme habitats such as hypersaline lakes, atoll lagoons, and hydrothermal vents (including Yellowstone). Now it’s possible to study how stromatolites form.

Stromatolites in Shark Bay, west coast of Australia (ours are much bigger!); source.

First though, let’s be clear: stromatolites themselves are not alive. They are structures built by resident organisms and the accumulation of sediment. Ancient ones, like those in the Medicine Bow Mountains, are fossilized stromatolites, with little or no organic material remaining.

The most abundant inhabitants of modern-day stromatolites are bacteria, specifically cyanobacteria. Like plants, they photosynthesize—convert sunshine to energy. Cyanobacteria are quite primitive, and were among the earliest forms of life on Earth. These were the builders of the Medicine Bow stromatolites.

Stromatolite construction begins when cyanobacteria form a thin sticky mat—a biofilm—on the floor of a shallow body of water. Sand and silt periodically wash in and settle on the floor, covering the biofilm. When the sediment gets too thick for sunlight to penetrate, the cyanobacteria move up to colonize a new surface.

This happens repeatedly, producing a stack of thin alternating layers: biological, sedimentary, biological, sedimentary, etc. Cyanobacteria occupy the upper surfaces, basking in sunshine. Meanwhile, the layers are cemented with calcium carbonate, either from the water or the bacteria (or maybe both, we’re still learning). Without this cement, stromatolites wouldn’t survive a hundred years, much less two billion.

WYOMING BY THE SEA

Two billion years ago, Wyoming was located on the coast of a much smaller North America. Our stromatolites stood in warm shallow saltwater; in the absence of predators, resident cyanobacteria flourished in the sunshine. But these good times were not to last.

About 1.75 billion years ago, the coast was subjected to continental collision—goodbye ocean!—accompanied by mountain-building, which tilted the horizontal stromatolite-bearing rock layers to near vertical. Then 60 million years ago, there was more deformation when the Medicine Bow Mountains were pushed up during creation of the Rocky Mountains. This was followed by tens of millions of years of erosion culminating in scraping, planing, and polishing by glacial ice until just recently (about 11,000 years ago).

Now these relics of a subtropical ocean lie far from any coast, over ten thousand feet above sea level, and covered in snow for half the year—a graphic example of the dramatic change possible with the immensity of geologic time.

Actually, given all that has happened, it’s quite remarkable that the stromatolites of the Medicine Bows have survived. That they remain largely intact and recognizable is a stroke of good fortune for us— we can stroll among ancient stromatolites, ponder the passage of two billion years, and imagine a very different world. But to find this world, we need a guide.

NOW YOU CAN SEE FOR YOURSELF

In the mid 1960s, fifty years after he worked with Eliot Blackwelder in the Medicine Bow Mountains, Samuel H. “Doc” Knight—by then a highly-respected geologist, beloved teacher, and professor emeritus at the University of Wyoming (UW)—finally found time to study the local stromatolites:

“The writer has visited many of the stromatolite occurrences with student groups during the past forty years. Only recently, upon his retirement, did the opportunity present itself to undertake a detailed study of the occurrence and character of these stromatolites.”

One of many detailed illustrations in Knight's 1968 paper. Added arrow points to stromatolite in Blackwelder's paper and last photo of this post.

Knight spent six months in the field, over the course of three seasons, assisted by his grandson David Keefer. They mapped, measured, described, drew, and photographed 150 stromatolite-bearing outcrops.  Knight’s pioneering paper, Precambrian stromatolites, bioherms and reefs in the lower half of the Nash Formation (1968), drew international attention. As a result, the UW Department of Geology and Geophysics and the UW Geological Museum fielded numerous inquiries: “Where are the stromatolites in the Medicine Bow Mountains? How do we get there?” After forty years of this, it was clear that an updated publication was needed.

Professors Donald W. Boyd of UW (who was introduced to the Medicine Bow stromatolites by Doc Knight, in 1956), and David R. Lageson of Montana State University devoted themselves to the task. They relocated, photographed, and took GPS waypoints for many of the stromatolites described by Knight, and developed a walking tour that includes some of the best examples. Their Self-guided walking tour of Paleoproterozoic stromatolites in the Medicine Bow Mountains—“an illustrated field guide to some of the world’s best stromatolite outcrops”—was published in 2014 by the Wyoming State Geological Survey. It’s available free online.

The guide includes information about stromatolites in general, as well as those of the Medicine Bows. This is followed by the walking tour, and directions to other sites. While much of the text is technical, the introductory material, map, photos, and GPS coordinates will be useful to anyone who wants to stroll among our stromatolites, and contemplate the immense changes in the Earth that they represent.

The most accessible stromatolites lie adjacent to the road into the Sugarloaf Recreation Area, just a half-mile from the Snowy Range Road (Wyoming 130). The cabbage-like structures are obvious (left photo, with Professor Boyd). It’s easiest to park at the Sugarloaf Picnic Area (pass required), and then stroll a quarter mile back to the site. For details, see “STOP #10” in the guidebook.

Guidebook author Don Boyd kneels by stromatolites along Sugarloaf Recreation Area Road. Having been tilted 90º, they’re now seen in cross-section, as “cabbages.” Arrow shows original orientation—youngest growth surface on the right.

Those who are more adventurous will want to do the walking tour, which includes the famous Big Daddy at Prospector Lake, and the wonderful Valley of Stromatolites (right photo). The tour traverses an old road, overgrown in places, and includes several cross-country options. Distance is roughly 1.5-2.0 miles, depending on options. Follow the guidebook’s detailed directions carefully, and refer to the excellent photos. For reassurance, bring a GPS-capable device. The tour starts off Forest Road 332 (dirt), which is rough and rocky in places. Snow can be late in melting. For conditions, check with the Forest Service office in Laramie.

Arrow points to famous 15-ft long compound stromatolite in the Valley of Stromatolites. Original orientation inferred from arching layers—“top” marks youngest growth surface. Blackwelder sent a photo of this "large dome-shaped structure" to Walcott at the Smithsonian, and included it in his 1926 paper.

Great Skyroad Opens Wonderland to Public Travel

Cars on Libby Flats at the base of the Snowy Range, southeast Wyoming; July 4, 1926; courtesy American Heritage Center, University of Wyoming.

This article will appear in Sunday's Laramie Boomerang, our daily newspaper,  founded in 1881 by Bill Nye. He named it after his mule “who always came back.” I contribute to the popular “Laramie’s Living History” column, usually writing about botanical and geological features. But this is all human history, with the exception of some “glacial ice.”

Celebrating the “Great Skyroad”

On the morning of July 4, 1926, it was raining hard. But that didn’t stop the watermelon crew. They left Laramie early, reaching the summit well in advance of the ceremonies. There they buried two tons of melons in snow. Unfortunately, by mid-day the new road was thoroughly soaked, and struggling automobiles had churned it into an unnerving muddy mess. Many turned back. The Governor arrived two hours late.

Yet the ceremony went largely as planned, with hundreds of chilled but cheerful onlookers celebrating the opening of the Great Skyroad across the Snowy Range. Though the name didn’t stick, the road was a great success, opening areas previously inaccessible, and allowing for many activities across the range.

FIFTY YEARS OF IMPROVEMENTS
The first wagon roads into the high Medicine Bow Mountains appeared in the 1870s, built by loggers, miners, and tie hacks from the railroad. By the late 1890s a road of sorts extended across the range. But sections were quite rough, barely passable to wagons.

In 1909, the Forest Service, Albany County, and the town of Centennial contributed a total of $2500 for road improvements between Centennial and Brooklyn Lake. The first auto arrived at the lake a year later, a new Franklin driven by Forest Supervisor P.S. Lovejoy. The nine-mile trip (one-way) took an hour. Lovejoy must have been an adventurer and skilled driver, for the road to the lake was said to be impassable to autos, and would remain so for a decade.

[NOTE: This Lovejoy is not to be confused with Laramie’s inventor Elmer Lovejoy, of bicycle and automobile fame, and it’s unknown whether the two were even related. But Supervisor Lovejoy may well have bought the Franklin he drove to Brooklyn Lake at Lovejoy Novelty Works, where Elmer sold both bicycles and automobiles. P.S. Lovejoy left Laramie around 1911, moving to Ann Arbor to teach in the Forestry program at the University of Michigan.]

Elmer Lovejoy’s Garage and Service Station c. 1920; courtesy Laramie Plains Museum.

In 1920, the federal Office of Public Roads and Rural Engineering (today’s Federal Highway Administration) provided Wyoming with $25,000 to improve the road to Brooklyn Lake, which had become popular with local recreationists and, increasingly, tourists. Those sections not covered by the feds were upgraded by Albany County.

The obvious next project began in 1924—a road passable to autos across the high Medicine Bow Mountains. Fully funded by the federal government, it would continue 22.5 miles west from the Brooklyn Lake road to the Forest boundary, where it would join with an existing road from Saratoga. The roadway would be ten feet wide with a surface of graded dirt (graveling and then paving of the Snowy Range Road didn’t start until the 1930s).

BIGGEST PICNIC EVER

By the summer of 1926, the road over the Medicine Bow Mountains was essentially in place. A dedication ceremony was in order, and what better day to celebrate than July 4, our nation’s birthday. A committee was formed, and plans were made. On July 3, the Laramie Republican-Boomerang announced that the dedication exercises, which would start at noon, would be followed by “the biggest picnic ever held in the state.” Watermelons chilled in “glacial ice” and hot coffee would be provided. Attendees were to bring their own lunches.

But first the road had to be cleared of snow on both sides of the summit—not surprising given the earliness of the season. A call for volunteers went out. The Wyoming Reporter, a Rawlins paper, assured readers that a crew of 30 had successfully cleared the route with picks and shovels, though in places autos would have to pass between snow banks 10 to 15 feet high. Saratoga and Centennial supplied most of the volunteers, along with a few from the University (including President A.G. Crane). Notably, even though a “large number of people from Laramie were in the Snowy Range region … few volunteered to help open the road.”

On July 1, special traffic regulations for the day of the celebration were announced in the Laramie Republican-Boomerang: “Forest and sheriff’s officers will be stationed at key points along the highway, and between the hours of 10 and 12, only ‘up’ traffic will be permitted. Between 12 and 2 will be reserved for ‘down’ traffic and the hour between 3 and 4, if necessary for ‘up’ traffic. A speed limit of fifteen miles per hour will be in effect on all sections of the road where the need warrants.” As it turned out, 15 mph was overly optimistic.

BRAVE DRIVERS REAP REWARDS

July 4 dawned rainy, with especially heavy downpours on the east side of the range. This “greatly hindered the progress of the multitude of automobiles that had come for the exercises” according to the Laramie Republican-Boomerang. The wheels of hundreds of cars soon made the road slick and dangerous. Many turned back, especially those from Laramie and Cheyenne, the road up the east side being particularly treacherous.

However state officials led by Governor Nellie Tayloe Ross, along with representatives of the Forest Service and dignitaries from Rawlins, Laramie, Cheyenne, Parco, Saratoga and Encampment, braved the conditions and reached the summit, though two hours late. But that was just as well, as the skies had cleared only an hour before.

There they found either 400-500 (Rawlins Republican) or 600-700 (Saratoga Sun) participants in a celebratory mood. A huge fire roared nearby, and, at the encouragement of President Crane, people were loudly singing “It Ain’t Gonna Rain No More …”

A speaker’s platform had been assembled from two table tops, laid across the sides of a truck. Here the most important dignitaries sat while Governor Ross dedicated the “Great Skyroad” (see photo). The Laramie Republican-Boomerang would report the following week that “Governor Ross made a particularly fine appearance that morning, standing up there on the roughly improvised platform, and her voice which is especially clear and pleasing, seemed to reach even the outer edges of the crowd, who paid their marked attention.”

Warmed by a roaring fire, Governor Nellie Tayloe Ross (standing on platform) dedicates the "Great Skyroad" over the Snowy Range; July 4, 1926; courtesy American Heritage Center, University of Wyoming.

According to the Boomerang, ceremonies were carried out as planned “with some necessary omissions.” Hundreds of chilled watermelons were enthusiastically consumed. However, the Rawlins Republican reported that participants from the west side of the range were “sadly disappointed” when the promised hot coffee was nowhere to be seen on Libby Flats. Instead, it was available 15 miles down the road toward Laramie, where lunch for the official party was being served. Given the slippery roads, a 30-mile side trip did not appeal to those returning home to the Platte Valley. “Why the coffee was not served at the point where the exercises were held is a mystery.”

The following week, local papers were in general agreement that the ceremonies and especially the new road were a great success. The Boomerang argued that given the morning’s storm, “it would not be fair to judge the road by its condition on Sunday … any road having something like half a thousand cars churning over it both coming and going is bound to manifest the effects.” Those who reached the summit and even those who made it just partway “were enthusiastic with what they saw, the wonderful vistas of mountains in the distance and the plains stretching beyond the almost countless lakes and ponds of beauty and the rushing, tumbling streams.”

The Saratoga Sun was equally effusive but more succinct: “In spite of the discomfort occasioned by the downpour of rain, however, all were agreed that the new highway has opened to public travel a wonderful scenic region, which will no doubt prove to be a favorite resort for outers and vacationists during this and succeeding summer seasons.” So true!

[by Hollis Marriott, Contributing History Columnist; Laramie Boomerang, August 18, 2019]

Sources

Wyoming Highway Department & Federal Highway Administration. 1988. Dedication ceremony; New Wyo 130 (Snowy Range Road). 12 pp.

Wyoming Newspapers. Online database. https://newspapers.wyo.gov/ (accessed August 2019).

In Search of Layered Pond Muck

There's a story here.

We were making slow but steady progress up the narrow valley of Libby Creek, across unvegetated hummocky ground covered in boulders and snow, through a network of cold sediment-laden creeklets. But just as we caught sight of the snout of the glacier ahead, we were stopped by icy torrents emerging from the fractured dirty ice. Water came roaring down the canyon, rolling and bashing boulders. It was only June, but the onset of melting had opened tunnels and drainages in the ice, and the annual flood was underway.

We headed back, stopping at one of the ponds among the hummocks of glacial till, where we ate lunch perched on quartzite boulders above the cold wet ground. The pond was mostly ice-free, the water murky with sediment carried in by streams. I tossed a penny into the pond—not for a wish, but to confuse future glaciologists.

Then my ice age dream vaporized and I was back in the aspen stand, staring at layered dirt.

From gravel pit near Barber Lake, 1972; photo by Wayne Sutherland, pencil for scale (Mears 2001).

Learning geology is learning to read ... not books, but landscapes, rocks and dirt. Like books, they take us into other worlds—even the far distant past. But the entryways aren’t always obvious. For example, few people would stop to examine the drab dirt slope in the photo above.

That photo has appeared in several publications about the geology of the Medicine Bow Mountains of southeast Wyoming. The outcrop was said to be located just west of Centennial, which is just 30 miles from where I live. Of course I wanted to see it, so I read the description carefully.

“… recession of the ice in the broad canyon west of Centennial left hummocky till behind. Trapped meltwater created a pond here which is recorded by thin varves of sand and pebbles washed in during summers, and silts that slowly settled when the pond’s surface was frozen. The varves, now exposed in an old gravel pit near Highway 351 [Barber Lake Road], are overlain by till of a second advance.” (Mears 2001)

Medicine Bow Mountains during the Pleistocene. Arrow marks location of pond sediments exposed in an old gravel pit. Diagram and drawings by SH Knight (1990).

I drove the Barber Lake Road from top to bottom, searching for an abandoned excavation, but found nothing. Then I checked around the various campgrounds … still nothing. Maybe it’s gone, I thought—buried, eroded away, or turned into a campsite. After all, 45 years have passed since that photo was taken.

But I didn’t give up. Instead, I did what any wise person would do: I asked a librarian, specifically the Centennial librarian …

The librarian didn’t recognize the layered dirt in the 1972 photo, and didn’t know of an old gravel pit near Barber Lake, but she did know several people who might well know, and indeed one of them did know: “just off the Willow campground road near the entrance gate, on the left.”

A week later, I parked near the campground gate. Through aspen trunks, I spotted a promising pale outcrop and headed over for a closer look. Yes! This was the old gravel pit, now overgrown with aspen. Even after 45 years of weathering and erosion, layers were still distinct in places, though not as fresh as in the old photo.

Gerard De Geer of the Geological Survey of Sweden was the first to figure out the stories told by what Swedish geologists called hvarfig lera (layered clay), now called “varves.” Varves are like tree rings. Each one represents a year of activity—growth in the case of tree rings, and sedimentation in the case of varves. De Geer constructed the first varve chronology, published in 1912. Since then, the Swedish Varve Chronology has grown into a 14,000-year record of floods, drought, rains of volcanic ash, deglaciation, plants (pollen), and more.

The varves in the Medicine Bow Mountains date to roughly 10-15,000 years ago, when the crest of the range was covered by an ice cap, and a glacier extended down the Libby Creek drainage. During the warm season, streams from the glacier brought down sediment—more or less depending on the amount of melting and vigor of the streams. Some of the sediment ended up in ponds in the moraine and hummocky till (unsorted sediment) below the glacier. After a short “summer,” the ponds froze over. Then the finest particles slowly settled out, forming a thin band of clay on top of summer sediments. Gravel quarrying exposed part of the varve record of one of these ponds.

A layer is a year’s worth of sediment. Arrows point to clay bands marking end of annual cycles.

Do thinner varves above the thicker one tell of less melting and sedimentation? Or was the glacier farther away, melting back to the high country? Our chronology is too short to say. We need more varves, probably a lot more.

More than once I’ve wondered if rocks and dirt are as easy to read as their stories in print suggest, but rarely can I judge. However, in this case I know there's another version of the story. The great Samuel H. Knight—Mr. Geology of Wyoming—concluded that the varves formed in a moraine-dammed lake rather than in a pond in hummocky till.

“Accumulations of unsorted rock fragments transported by ice were deposited in moraines on valley floors, behind which lakes were impounded in which distinctly laminated, fine-grained sediments (varves) were deposited.” (Knight circa 1974, published 1990)

Libby Creek terminal moraine and impounded lake, in which varved sediments were deposited. Cross section shows relationships of various glacial sediments (Knight 1990).

Whether deposited in ponds or lakes, surely more varves lie hidden under today’s soil and plants. So hikers and mountaineers, keep an eye out. Among all those lodgepole pines and grouseberry bushes, there may well be entryways to other worlds!

Some climb mountains “because they are there”

Others climb mountains their secrets to share,

For mountains hold in their massive grasp,

Profound records of the infinite past. 

– Samuel H. Knight

Sources

Thanks to Deb and Lowell for directing me to the varves.

Knight, SH. 1990. Illustrated geologic history of the Medicine Bow Mountains and adjacent areas, Wyoming. Geological Survey of Wyoming Memoir 4. PDF

Mears, B, Jr. 2001. Glacial records in the Medicine Bow Mountains and Sierra Madre of southern Wyoming and adjacent Colorado, with a traveler's guide to their sites. Geological Survey of Wyoming Publ. Info. Circ. No. 41. PDF

North American Glacial Varve Project, Tufts University.