The second-largest giant sequoia in the world.

A haven for wildlife amid the farmlands and development of the Willamette River Valley.

Named for a prominent scout and explorer, this Wyoming state park encompasses a replica of an 1840s trading post, a 19th-century Army outpost, and early 20th-century automobile lodgings.

Cross the Continental Divide through an old railroad tunnel, and ride back to the top on a shuttle.

A large wind turbine installation in central Washington State is home to an extensive set of interpretive exhibits.

This lighthouse has been guiding shipping into the Golden Gate since before the American Civil War.

This open-air reconstruction of an Old West town, a cross between a theme park and a museum, provides an immersive historical experience.

A late-19th century diversion canal built by hand crosses Bryce Canyon National Park and is still in use.

A remarkably well-preserved stage stop from the late 19th century in a remote part of Nevada.

The only bridge in the United States where BASE jumping is legal without a permit year-round.

A mine in the Sierra Nevada that produced nothing but barren quartz.

A well-preserved sheepherding camp now lies in the heart of the Granite Chief Wilderness, in the high Sierra Nevada.

A well-preserved example from a 1920s network of airmail navigation arrows sits near Interstate 15 in southern Nevada.

Atop an active stratovolcano, two lakes separated by a narrow strip of land.

One of the most elaborate displays of Jellyfish is on display at the aquarium.

The original span of a high bridge across the deep Crooked River Gorge has been preserved for pedestrian use.

An early 20th-century fire lookout, still in intermittent use, preserves legacy fire-locating equipment.

A scenic hike in the High Sierra that ends at an old gold mine.

A converted hangar displays dozens of helicopters, from a famous 1943 rescue chopper to several autogyros.

A well-preserved example of an early industrial operation in the northeastern United States.

Decor at “Nevada’s Oldest Thirst Parlor” includes Raquel Welch's brassiere hanging from a stuffed moose head.

An unusual slot canyon in the Aztec/Navajo Sandstone has a cross-section like an inverted old-fashioned keyhole.

One of the largest wildlife refuges in the contiguous 48 states, it was instrumental in preserving the pronghorn antelope from extinction.

An unprepossessing storage reservoir in southern Utah has a checkered past.