Yellowstone is full of hot springs like this one. Most of the color is due to various forms of algae and bacteria that thrive in the unique chemistry of these places.

These poisonous pools smell very bad, but look very pretty.

There are dead trees throughout the park. Many are from the great fire of 1988, but I think these may have been killed by advancing mineral efluent.

The park is recovering well from the '88 fires. These flowers were gorgeous.

Nothing is quite as creepy as boiling, sulphurous mud.

The park is littered with these hot springs.

This is Morning Glory spring. Apparently, people throw all kinds of objects into it, which has reduced its color over the years. Why would anyone do that?

Nasty and poisonous, but beautiful.

This is another place where the trees may have been killed by the chemicals oozing from the springs.

The crust around these springs is thin, and therefore very dangerous to walk on.

The organisms that live in these springs are highly exotic, and probably much like the original forms of life that colonized the earth.

Weird pebbly things composed of "Sinter," growing from the chemicals dissolved in the water.

The sun, as seen through the vapors belching from Mammoth Hot Springs. I'd love to take credit for this shot, but I took it after I saw a Chinese tourist take the same picture.

This is the view from the south end of Mammoth Hot Springs.

This is one of the most active parts of Mammoth. Over the years some of these springs die, while new ones spring up.

These trees were certainly detroyed by the advancing springs.

Another view from the south end of Mammoth.

Algae and other organisms made an interesting background for this dead tree.

This is what the terraces at Mammoth look like while they're active. Once the water stops, they rapidly lose their color.

Here's where I started into the abstract stuff. Yeah, I know: It's pompous.

Amazing colors in this stuff. I'm sure this is the kind of thing Dante had in mind for Inferno.

Look closely, and you can see the Bison prints in this colony of algae.

Weird, eh?

For some reason, these abstract things look best when cropped to a square format. Makes me long for my Hassselblads.