Before reaching Yellowstone, we stopped along the road to examine these ancient lava flows.

Entering Yellowstone National Park.

Low and behold, right after entering the park, we caught sight of this Bison.

An impressive flow of water from the Silex Spring. Bacteria and other thermophiles thrive in the hot water, giving the spring its distinctive color.

The Celestine Pool.

An eruption of hot water from the almost continually erupting Clepsydra Geyser.

The Chinese Spring, near Old Faithful.

Blue Star Spring.

Old Faithful erupts, as it does regularly with a period of about 90 minutes.

A collection of springs in the West Thumb area, overlooking the vast Yellowstone Lake.

More springs at West Thumb.

A sputtering spring.

Abyss Pool.

Black Pool.

"Big Cone" juts out from Yellowstone Lake.

A bubbling mud pot.

Some roaming bison.

Pretty clouds.

Me in front of the Yellowstone River.

A bison up close.

A large heard of Bison along the Yellowstone River.

A view of Lower Falls, as seen from Artist Point, one of the best views in the park.

Helen at Artist Point, which looks into the Grand Canyon of the Yellowstone River.

Some grazing elk.

The tourists like to get a bit closer to the elk than they should.

Sunset in Yellowstone National Park.

After spending the night in Gardner, Montana, we returned to Yellowstone Park. In the morning, we were greeted by these deer hanging out in the Mammoth Hot Springs area.

Helen in front of the Main Terrace.

Close up of the Main Terrace.

The Main Terrace.

Me in front of the Main Terrace.

A petrified tree.

A view of the Yellowstone River near the Tower-Roosevelt area.

Tower falls.

Driving through the endless expanse of Montana in order to reach Buffalo, Wyoming for our next night's stay.