Geysers and bison at Yellowstone
The wildlife at Yellowstone National Park is really amazing: wild bison, elk, herds of deer, and more. I'm not sure, but I'd imagine the name "yellow stone" must come from all the colors in the geyser and hot springs. Given the volcanic activity, the springs are constantly evolving. The forest, though, is the same untouched wilderness as it has been for generations, except for a few traces from the Great Fire of 1988.