Yellowstone, established in 1872 by Ulysses S. Grant, was the first National Park in the world. Originally managed by the U.S. Army, it was transferred to the infant National Park Service in 1917. The army infrastructure remains at Mammoth Hot Springs and is still used by NPS. The park is centered over the largest still active supervolcano in North America (yes, Virginia, there is a wee bit of factual basis for a wee bit of the movie 2012.) The bullseye for the caldera is Yellowstone Lake, which rose nearly 30 inches between 1923 and 2004, and lately has been rising nearly three inches a year. Fortunately, scientists think that the magma is still deep enough that we aren't in for any immediate problems. Still, there are frequent earthquakes releasing pressure.
So . . . there we were, only 40 miles away, and a whole day to use exploring. Little did we know that Yellowstone is not a dog-friendly place, so it was tricky to get Ella's walks in.
The first thing most people think of in Yellowstone is geyers, especially Old Faithful.
Next usual thought: Animals, specifically bears and bison. We didn't see bears here, but the bison were healthy and magnificent. We also saw lots of chipmunks and ravens.
What a great surprise — the Grand Canyon of the Yellowstone. Every view was a delight, in spite of the smoke.