A close call with some roaming Bison in Yellowstone. Fortunately they found a smaller car to tip over.

Warning - a bit of panic induced language in this one.

Old Faithful geyser, shortly after one of its many eruptions
Another encounter with Yellowstone's largest wildlife. In this case, we were in Hayden Valley when we noticed them swimming across the corner of Yellowstone lake. We stopped further up the road and waited (and waited) as about forty of them crossed.
Norris Basin, one of the many areas of geothermal activity in Yellowstone NP. For a photographer the colors alone are a great attraction, but there are also geysers scattered all over the place, a lot of hissing stem vents and from time to time a not so nice smell...