The second, too-brief part of the trip took us to Yellowstone. First stop was the Grand Canyon of the Yellowstone, and this view of Lower Falls.
At the Midway Geyser Basin, I found possibly the quintessential Yellowstone image: the colorful, deceptively-placid waters of Opal Pool with a typical Wyoming landscape for a backdrop.
Part of the adjoining Turquoise Pool.
Excelsior Geyser isn't technically a geyser anymore, as repeated eruptions dislodged the constriction that distinguishes a geyser from other thermal features, and now it's merely another hot spring, albeit a large and colorful one.
From the time I first considered visiting Yellowstone, there was one site I wanted to photograph more than any other: Grand Prismatic Spring. However, the cold and windy weather was to play a trick on me here, as it was producing so much steam (usually blown right in the direction of the boardwalk) that the spring itself was usually invisible. Finally, on our way out of the park, I stopped for one more try and, this time, was able to get some abstract glimpses through the steam when the wind shifted.
Finally, is there any need to even identify this subject? Eruptions every 93 minutes or so -- and, that morning, I was lucky enough for it to take place just as the omnipresent cloud cover broke and allowed me a patch of blue sky for the background.
As we left the park on our way back home, it started to snow...