Geological Setting of Yellowstone National Park (click for larger version)

Did you know that geologist Jo-Ann Sherwin and I spent a lot of time updating the geology in the latest edition of Yellowstone Treasures? This map we revised is the most technical one, not intended for navigation like most of the 38 maps in the guidebook! Besides the types of rock in the different mountains, the map shows calderas. (A caldera is a large circular or elliptical crater or depression formed by the collapse of a large land area after the emptying of a magma chamber in a massive volcanic explosion.) Notice how the most recent—and famous—Yellowstone Caldera is marked with a solid line because much of its edge is visible at the surface. Meanwhile, the Henrys Fork and Huckleberry Ridge Calderas have a dashed outline to show that the caldera edge is buried under more recent volcanics. East of the park, the dotted outlines of the Heart Mountain detachment and its remnants show their general size, shape, and location. These are large chunks of Paleozoic sedimentary rock that became detached from the underlying rock and slid to the southeast over the Bighorn Basin. There’s lots more to explain calderas and other geological formations in the guidebook’s Geological History chapter.

We welcome your feedback on either our books or this website. Contact us!
—Editor Beth Chapple

Map credit: Jo-Ann Sherwin adapted this map with permission from Mountain Press’s Roadside Geology of Wyoming, 2nd ed., 1991, by David R. Lageson and Darwin R. Spearing.

Elsewhere on this website you can read about “The Yellowstone Caldera” and the Heart Mountain Interpretive center: https://www.yellowstonetreasures.com/2013/07/14/trip-report-heart-mountain/.

Cliff Geyser on Iron Spring Creek

Recently we happened upon this 2015 Q&A on Quora.com that busts several myths at once, in a friendly and concise way.

Q. Does it look like Yellowstone is going to erupt soon?

A. There are no signs that we know of that point to an eruption any time soon. However, since we have never seen a volcano like Yellowstone erupt, we can’t be sure what the warning signs of an eruption would be. Some sensationalist sources take every little twitch from the volcano, and even events unrelated to geologic activity, as signs of an impending eruption. Don’t take them seriously.

In better news, at least one study has suggested that the magma chamber beneath Yellowstone is partially solidified to the point that it currently cannot erupt unless it gets a fresh batch of hot magma from the mantle.

One little misconception that should be covered here: Yellowstone is not “overdue” for an eruption. The little factoid that Yellowstone erupts regularly every 600,000 years is untrue. So-called super eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago, which gives intervals between eruptions of 800,000 and 660,000 years, though three eruptions are not enough to establish a reliable recurrence interval.

Credit: This answer on Quora was written by Nicholas Schiff, B.S. Geology, Mercyhurst University, Erie, PA.

In the guidebook: There’s much more in Yellowstone Treasures about the Yellowstone hot spot and supervolcano, especially in the Geological History chapter, pages 303 to 318.

This photo of a major eruption of Steamboat Geyser gives a sense of its power but not its full height!

Here are a few of the geyser changes since the cutoff date for the first printing, February 2017. During 2017 Atomizer Geyser (p. 96) noticeably slowed its interval down from twice a day to an average of 20 hours. Page 93 of the first printing says Giant Geyser last erupted on September 28, 2015 (and that was after a five-and-a-half year hiatus, so it was pretty important). But nature has been busy proving the guidebook wrong. Giant erupted on July 7, October 9, and November 3, 2017, so we included the November date as the last eruption. Now the most recent eruption was actually July 24, 2018, and that was the third time in the month of July.

We are fortunate to have a website called GeyserTimes.org, where geyser gazers can log their observations or the notes from a ranger or scientist at the US Geological Survey (USGS) Yellowstone Volcano Observatory. Readings from seismometers, thermometers, and water discharge monitors are used to record eruptions even when nobody is there to witness them. That is how we know that Steamboat Geyser started erupting again on March 15, 2018, too late to get into the second printing. On page 233, it unfortunately still says “After eruptions in 2003 and 2005, Steamboat erupted once each in 2013 and 2014.” Yet as of today there have been 11 more since March 15, with the latest occurring on July 20, 2018! The USGS is keeping a running count of Steamboat’s water eruptions at the Yellowstone Volcano Observatory page.

You may have a chance to see the Giant or Steamboat Geysers on your trip to Yellowstone. Stay informed with Yellowstone Treasures, both the book and this website.

—Beth Chapple, editor and publisher

Photo credit: James St. John, June 4, 2018. Reproduced courtesy of a partial Creative Commons license. More photos and more about the history of Steamboat Geyser is available at on the geologist’s Flickr page for this photo.

Abiathar Peak

You can read the nugget “How did these mountains get striped?” to see the new explanation. Stay informed with Yellowstone Treasures, both the book and the website.

Photo by Niklas Dellby, 2013

A sign of spring: adult Western Tiger salamanders come out from hibernation in late April to June, depending on elevation, and migrate to breeding ponds where they lay their eggs.

For example, an alert issued yesterday tells us that although Norris Campground was scheduled to open Friday, May 18, the opening will be postponed. In preparing for the spring opening, they discovered leaks in the water lines, and there’s no potable water. The savvy traveler needs to check that kind of information too!

Since changes to the park’s roads, trails, geysers, fees, and even scientific knowledge are so frequent, we have a lot to check for every edition of Yellowstone Treasures. For this spring’s second printing of the guidebook, we made enough changes that we changed the title page to read “Newly revised for 2018.” Soon we will start an occasional series outlining some of the revisions to give you a flavor for what has changed, called “Updated for 2018.”

—Beth Chapple, editor and publisher

Photo credit: The picture of Yellowstone’s only salamander is an NPS photo by Jeff Arnold.

Trained as a medical doctor at Albany (NY) Medical School, Hayden served as a surgeon in the Union Army until 1865. However, he became interested in geology through collecting and studying fossils in the Dakota Territory and in 1867 began his government-supported geological surveys of the west.

During the summers of 1871, 1872, and 1878, the Hayden Survey studied the Yellowstone area systematically. The men observed and reported on many geological and other phenomena in voluminous reports. The report of Hayden’s first exploration was essential in convincing Congress to establish YNP in 1872.

Hayden’s love of geysers and hot springs reportedly could move him to tears. As an early guidebook writer observed: “He cannot compose himself in the presence of a geyser in eruption; but, losing recollection of the material world for the time, rubs his hands, shouts, and dances around the object of his admiration in a paroxysm of gleeful excitement.”

Since 2011 Montana and Idaho have been conducting managed wolf hunts, but in Wyoming a U.S. Court of Appeals has only this March approved a wolf-hunting plan that is deemed not to endanger the survival of the species in that state.

All the controversy about wolves stems from the 1995 and ’96 introduction of gray wolves (Canis lupus irremotus) into the park (and also into Idaho) from Alberta and British Columbia, Canada. Their population soared within a few years to around 150 wolves in the Greater Yellowstone Ecosystem, and scientists like Dr. Douglas Smith found, as quoted by Robbins, that “Yellowstone is the best place in the world to view wolves”—and to study them. This is especially true because the Yellowstone wolves do not fear the thousands of eager visitors who flock there—and incidentally add money to the regional economy. The wolves are thus quite readily visible.

In the years after the introduction of wolves, neighboring ranchers were understandably distressed. Some of their cattle, sheep, and even dogs were killed; before wolf hunting was authorized some ranchers were reimbursed by nonprofit organizations for their losses. It is hoped that protection within the park, combined with limited hunting outside its borders, will provide the needed balance and keep the population of Yellowstone’s wolves to approximately one hundred, as has happened in the last few years.

Robbins tells us much more about the results of research done by Smith and his colleagues. Longevity and social hierarchy within the packs are now better understood, and observation has revealed that wise older wolves serve an important role. Dr. Smith believes that packs are matrilineal. “Males come and go . . . but Gramma, Mom, and the daughter are the ones that stick around.” Here is a link to the whole article, “The New Threat to Wolves in and around Yellowstone.”

For some earlier blog posts about wolves here at YellowstoneTreasures.com, just enter “wolves” in the search bar.

Photo is of Yellowstone Forever Institute instructor Brad Bulin showing a wolf pelt, winter 2006. Photo by Janet Chapple.

But, if you are anything like me, you are mostly celebrating that the time for your summer trip to this wonderful park is drawing nearer. Just one thing that may give us pause as we contemplate the sights we are anticipating seeing: the crowds are likely to be amazingly large.

Here are links to a University of Montana report (2.7 MB pdf file) on 2016 crowding in that state’s two national parks and a shorter summary of the report, emphasizing Yellowstone, by Sean Reichard of YellowstoneInsider.com.

II.
If you should happen to be one of the people driving into Yellowstone this weekend, you may want to take part in tomorrow’s Earth Day Walk for Science at Old Faithful. This echoes the Washington, DC, Walk for Science. As an ever-curious non-scientist, if I lived anywhere near the park, I would certainly want to participate in that.

Janet on the north shore of the lake, 2009

While we recline in the doldrums awaiting the opening of Yellowstone Park’s roads—mostly on April 21st, when the bulk of the plowing should be done and wheeled vehicles can again reach the interior of the park—I will pass along a link about a man who is building a robot to learn what is below Yellowstone Lake and is yet to be discovered and explained by scientists. Elsewhere I learned that project leader David Lovalvo’s crowd sourcing for this project reached its goal of raising $100,000 last year.

Granted, this article appeared on the Internet a year ago, but its interest is evergreen. Geoscientists at the U.S. Geological Survey, particularly Lisa Morgan, Wayne Shanks, and Kenneth Pierce, published classic research papers on what they had learned by 2007*. But there is much more of interest lurking in the depths of the lake, and I only hope to live long enough to find out more about it.

*See the section titled “Yellowstone Lake Studies” in: Integrated Geoscience Studies in the Greater Yellowstone Area: U.S.G.S. Professional Paper 1717.

I’ve been following research on the wonders of the lake for many years, especially as written up by Lisa Morgan of the U.S. Geological Survey and involving the Global Foundation for Ocean Exploration’s Dave Lovalvo.

A quick apology: My long silence as a blog-poster or tweeter has been due to spending all my time promoting my new historical anthology, Through Early Yellowstone, and working on rewrites needed for a super fifth edition of Yellowstone Treasures.