Yellowstone National Park is unlike any other place on earth. One reason that I love Yellowstone is that, out of all the parks I’ve been to, it’s the one park where geology actually lives. You could stand in front of a glacier all day, and it’s not going to look like it’s moved much. Whereas in Yellowstone, you can go to the geysers and hot springs and actually see the park itself being active. There’s an interaction with the land and the sky and the wildlife. That’s what attracts me to the park; it’s constantly changing.

Looking back over more than twenty years of photographs, it’s clear how much the park has changed, both from the influx of tourism as well as the general activity of the region’s geological wonders. In Yellowstone, things change dramatically. One photograph, Minerva Hot Springs, has been one of the most unique hot springs in Mammoth Terraces. It has moved over the hill, at times up to 100 feet from where it originated. The last time I checked, for the last several years, it has been gone—totally underground. It’s somewhere, but not on the surface.