After a review by our consulting geologist, Jo-Ann Sherwin, we changed the sidebar on page 203, “Why do the mountains look striped?” The layers you can see on some mountainsides are not lava flows per se but deposits of material called tephra from volcanic eruptions. And the eruptions happened closer to 45 million years ago rather than the 50 mya it says in the first printing of Yellowstone Treasures‘s fifth edition and used to say in the nugget on this website.
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