Central Yellowstone Pt 1

The following table is from the class notes provided by Prof. Paul Doss to describe the rock types commonly seen in the Central Plateau or within the Yellowstone Caldera.

The spectacular Lower Falls of the Yellowstone River mark the transition into the Grand Canyon of the Yellowstone. Above the Falls, the Yellowstone River runs smoothly from the Lake (or at least from LeHardy Rapids (see later)) and goes through the Hayden Valley the former home of the ancient Hayden Lake. Glaciers moving down from the Beartooth Plateau in Wyoming formed an ice dam which backed up the Yellowstone River to form Hayden Lake. With some amount of warming the river broke through the dam and drained some or all of Hayden Lake. Likely this damming and releasing of water from Hayden Lake happened several times during the various glaciation periods.

Hayden Lake bottom consisted of fine sediments settling out of the river as it stopped significant flows. This bottom material became the basis for the rich grasses in Hayden Valley which supports the larger wildlife for which it is famous, e.g. bison, elk, and bears. As noted earlier the better the soils, the better grass is able to crowd out trees. Accordingly, one can use the presence of trees to identify features such as the old lakebed shorelines as noted below.

In addition, one can use the presence of trees to infer changes in soil composition and likely presence of rocks rather than soil. In this case, the poorer soils are likely due to rhyolite lava being near the surface.

Pictured below is an Everts Thistle which was one of the main foodstuffs, Everts lived on while wandering in the Park area. Didn't look that appetizing to me but then we had dinner waiting for us back at the Mammoth Dining Room!!

For those of you with an unquenchable thirst for knowledge, here is the story of Truman Everts according to the web site

"These days the only connoisseurs of the wildly abundant Everts Thistle are the ungulates who peacefully graze in Yellowstone National Park's vast wilderness. Humans can thank Truman Everts (in whose honor the plant is named) for eating their species quota of the semi-digestible plant.

Mr. Everts did not particularly enjoy eating thistles and he only made a habit of it after getting separated from his frontier companions. In September 1870, two years before Yellowstone was declared a national park, the 54 year-old Everts had joined up with the Washburn Expedition, a group sent to explore the region bordering Yellowstone Lake. Truman was by all accounts a gentleman and something of a scholar but his skill as a backcountry explorer could kindly be described as "deficient". Old Truman wasn't a particularly keen navigator (partially due to his atrocious eyesight) and early into the voyage he became estranged from the company with whom he had set out. That was not so bad since he still had the camaraderie of his horse and a majority of his supplies. Alas, the union with his equine pal was soon broken as well when the horse got spooked and hightailed in a direction Truman did not precisely observe.

Left with only the clothes on his back and the gear in his pockets Everts was a castaway in one of the most spectacular and deadly environments on planet Earth. Poor Truman was harassed by the wildlife, plagued with starvation, prone to delusions, and learned first hand why the term "hot springs" is an understatement. It was more providence than skill that kept him going for thirty-seven long days. He did employ the classic "eyeglasses to start a fire" routine, using a focused beam of light to ignite dry tinder. It is not recorded if he fried ants with his specs though he did successfully fry a good patch of the surrounding forest.

With winter threatening the enervated Everts resorted to living day to day, eating great amounts of the thistle that now bears his name and invoking the memory of his daughter to fuel his will to live. It was with great fortune a search party sent by friends discovered the emaciated Everts and slowly nursed him back to health. A little good water, rest, and a bear-oil laxative to cleanse the knots of thistle lodged in his intestines and Truman Everts returned to civilization not much worse for the wear. For all his bumbling ways, Everts was able to survive in an environment that would later claim victims much more competent in backcountry travel than he."

ELK THISTLE Cirsium scariosum Elk thistle has large, spiny, grayish-green leaves attached to a thick stalk, which may stand anywhere from four inches to four feet tall. The light lavender flowers are hidden and clumped among the foliage near the top. HABITAT/RANGE: Prefers meadows and other moist soils from foothills to mountain and subalpine zones. It is a common plant from British Columbia to Saskatchewan south to New Mexico and California. Blooms June to early August. FACTS/USES: Elk thistle, also know as Everts' thistle, saved the life of Truman Everts in Yellowstone National Park in 1870. Everts, an explorer, became separated from his group and his horse for 37 days. Because a botanist had remarked that the root of this plant was edible and nutritious, it was the only plant he knew was safe to eat, and he subsisted on the raw root.