This arid landscape was once a lush wetland. Today, it's a paleontological site filled with fossilized mammoths, sabertooth cats, and more.

These huge stone ovens in the desert fueled the Nevada silver boom, and may have also been a hideout for outlaws.

See Hoover Dam and the bypass bridge from a perspective usually off-limits to the public, and float the upper part of the Black Canyon National Water Trail.

These markers are used to document elevation changes around the famed dam.

This set of three large, volcanic hot springs is a favorite haunt for intrepid divers.

The remnants of a creative early method of wildfire prevention.

At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

Inside this striking glass building, visitors can see thousands of dinosaur fossils in the positions that nature deposited them more than 150 million years ago.

These elusive, isolated rodents evolved into a distinct, locally iconic subspecies.

Harder layers in colorful sandstone weather out as prominent “fins" and even more intricate and bizarre shapes.

Despite its name, this route in southern Utah offers a heavenly day trip.

Rippling sand dunes frozen in the Arizona rock.

Narrow slot canyons in a badland eroded into soft sedimentary rock provide an otherworldly landscape in this remote Nevada state park.

This quiet park's strange sedimentary spires were named after Kodak's color film.

Local lore holds that Butch Cassidy took an escape route through Red Canyon's sandstone hoodoos after an attempted murder.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

The cinder cone volcano with a less than complimentary name.

The lost ruins of the forgotten ferry lie hidden beneath the silt.

An Ancestral Puebloan ruin that appears to burst into flames in the sunlight.

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

The wreckage of a deadly bomber plane crash can still be found near an Arizona peak.

A hidden slot canyon in the southern Nevada desert makes an unexpected oasis and scenic hike.

A replica of the flagpole that gave a frontier town its name.