A beautiful geyser under environmental threat.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A volcanic landmark located on an Ice age lake bed.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

A volcanic fissure over two miles long and up to 70 feet deep.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

An abandoned Jazz Age dream home and con man's hideout in Death Valley.