[MUSIC PLAYING] SARAH URIST GREEN: There is an abundance of open space in Utah.

And we were there to see just a handful of spots within it, lured by the siren song of some of the best loved earthworks of the 1970s.

Would they live up to the hype?

Could they compete with this vast, unforgiving landscape?

And what, if anything, is happening out here now?

Driving north from Salt Lake City, its density dissipated quickly as we wound our way deeper and deeper into the countryside.

After two hours, we made a last stop at the Golden Spike National Historic site, where on May 10, 1869, the first transcontinental railroad was completed, joining East and West right here with the ceremonial golden spike.

From there, we waited for this kind gentleman to finish smoothing out the dirt road, and followed a sign pointing us toward our destination.

Robert Smithson's 1970 artwork "Spiral Jetty" extends off Rozel Point Peninsula on the northeastern shore of Great Salt Lake, which we caught glimpses of as we approached.

After a time, we rounded a low hill and passed the remnants of some old piers, and realized we were reaching the site, which Smithson wrote he liked because it, quote, "Gave evidence of a succession of man-made systems mired in abandoned hopes."

The jetty begins as an indistinct form, jutting out from the rocks.

But its spiral shape became more and more clear upon approach.

Over the course of about a week in April of 1970, a construction crew hired by Smithson moved from the shoreline over 6,000 tons of earth and black basalt rocks, to form this coil, 15 feet wide and 1,500 feet long.

And there you are.

There's no label, no instructions.

It tells you what to do, insofar as there really isn't anything else to do.

You walk it, making your way through rocks and sand, the spiraling shape giving you views in all directions.

All the while, you appreciate the many layers of time you're experiencing.

There's the geologic time you're made aware of, when gases trapped in erupting lava formed the pocked surface of the basalt rocks.

And you can't help but contemplate the particularity of the Great Salt Lake, the largest remnant of Lake Bonneville, which, during the Pleistocene Epoch, covered the western half of Utah and parts of Idaho and Nevada.

Since the current lake has no outlet other than evaporation, it's way saltier than seawater.

And since it's so shallow, the water level rises and falls dramatically depending on precipitation.

You're acutely aware of what's changed since Smithson made this, as the water met the edge of the coil in 1970, but submerged it just a couple of years later.

And it remained that way until 2004, when drought caused it to re-emerge.

It's been visible since, although its appearance shifts dramatically, precisely what attracted Smithson to the site.

Microbes and algae in the water can turn this north arm of the lake a distinct red.

And foam and salt encrust the jetty in other-worldly ways.

Smithson's study of science informed the spiraling shape of the jetty, referencing the molecular lattice of salt crystal deposits, as well as the spiral motifs of nearby American Indian rock art.

The piece was made to be experienced in person, of course.

But Smithson also gave it life through an accompanying essay and documentation, capturing aerial shots of the jetty and making a film about it.

I'd seen that documentation numerous times.

But being there in person far surpassed my high expectations, and quieted my inner critic, who worried that this monumental macho gesture might fall flat in person.

It did not.

To make "Spiral Jetty," Smithson researched and traveled extensively, looking at natural formations and prehistoric art with friends and with his wife, artist Nancy Holt, whose work we were on our way to see next.

They're both known as pioneers of the Land Art movement, when in the late 1960s and '70s artists look for ways to exit the studio and gallery and make art out in the world.

This time also saw the birth of the environmental movement, and a growing awareness of human impact on the planet.

Speaking of, we also passed Orbital ATK out here, which develops and test rocket launchers and ammunition.

We drove for several hours through Box Elder County, passing fewer and fewer cars as we went, making our way toward Nancy Holt's "Sun Tunnels," which was constructed between 1973 and '76, out here in the Great Basin Desert.

Simple signage reassured us we were on the right track.

And the road opened up to a flat expanse before us.

Holt wanted to ensure that the land around the piece remained clear and uninterrupted.

And to a large extent that has remained true.

"Sun Tunnels" is composed of four concrete cylinders, each nine feet in diameter and 18 feet in length.

They are aligned in pairs along the axis of the rising and setting Sun on summer and winter solstice.

The tunnels are striking to experience from within and without, framing views of each other and the desolate, magnificent landscape that surrounds.

Holes cut through the tunnels form the constellations of Draco, Perseus, Columba, and Capricorn.

And throw light into the interiors in changing ways throughout the day and at different times of the year.

The tunnels provide shelter from Sun and wind in a way that feels important in this wide-open space, and also provides scale, giving you an anchor of sorts in this vast expanse, a man-made frame of reference among all that surrounds you.

As you walk among, and between, and around the tunnels, 360-views are segmented and framed into more digestible portions, almost like a photograph.

Photography was central to Holt's practice.

And you can really feel that here, not just from the documentation of the piece that she acknowledged as a way of experiencing it, but from the way the piece functions, the way it directs and delimits your view.

Before either this or "Spiral Jetty" was made, Holt and Smithson traveled to Stonehenge and other prehistoric megalithic rock structures in England and Wales, also visiting ancient and medieval ruins, mining districts, and industrial sites.

These histories are very much alive in both works, giving us a long view of human intervention on the Earth, and providing destinations within this, our limitless universe.

The next day took us to Wendover, right on the border between Utah and Nevada, home to "Wendover Willy," several fine casino resorts, and a former Air Force base, which during World War II was the training site for the crews that carried out the atomic bombings.

The "Enola Gay," which dropped the bomb on Hiroshima, Japan, was housed in this hangar.

Wendover is also a home of the Center for Land Use Interpretation, whose Orientation Building is open every day and greets you with this message.

ANNOUNCER: Welcome to the Center for Land Use Interpretation's Wendover Orientation Building.

SARAH URIST GREEN: Inside, we found a wealth of information about the history and present of Wendover and the region.

The organization is dedicated to understanding the nature and extent of human interaction with the surface of the Earth.

They share information.

And they also encourage new explorations of the contemporary landscape, producing exhibitions and events, publishing books, and offering research resources.

In the past, they've offered partnerships and residencies with artists and anyone working in or around the field of land use.

And you can see evidence of these activities around town.

They occupy a number of Wendover buildings, including studios and the Residency Support Unit, an off-the-grid live/work facility.

And also this aptly named, partially missing building, which was once an armament and inspection building for the base.

It's currently home to an installation by artist William Lamson, which you can access anytime you like by opening the black box to the left of the gray door, entering 1212 into the key box, and then using that key to open the gray door.

Don't forget to lock it and return the key when you're done.

Inside, you'll encounter "Mineralogy," a multi-year installation that transformed a former bathroom into the space you see here, a room just one foot shy of the interior dimensions of Thoreau's cabin at Walden Pond, filled with a variety of artifacts and vessels that have been repeatedly filled with salt water and allowed to evaporate.

You see it through viewing windows, that both protect the work's delicate salt crystal formations and also give you the distinct feeling that you're viewing a scene from the past.

Lamson brought together a variety of objects to set the scene, including a number of books, and pictures, and objects that his dad used to keep in their basement.

Salt has encrusted the vessels and expanded onto their surroundings, extending into delicate columns and dripping down the walls.

Books have bloated with saltwater, and in some cases tumbled to the floor.

When the artist is away, a solar-powered system turns on once a day to irrigate the space.

But he was in town, and we followed him as he went to collect fresh saltwater to refill the installation storage tanks.

The salt flats just east of Wendover have been mined since World War I, extracting minerals from the flats by flooding and draining vast areas and bringing the minerals into solution.

Evaporation ponds dry out undesired minerals, and eventually leave behind potash and magnesium chloride.

This operation, Intrepid Potash, has given Lamson access to their ponds and saltwater for free, which he pumped from a collection pond as we explored the sweeping alien landscape that surrounded us, which I kept having to remind myself was not covered in snow.

Tanks replenished, Lamson refilled the vessels within the installation, to allow the geologic process to continue and the work to further develop and transform.

There's a clear connection between what he's doing here in Wendover and Smithson's Utah efforts, exploring the effects of time, allowing for and encouraging the natural, inevitable disintegration and evolution of our physical world.

On our way out of town the next morning, we made a final stop at the Bonneville Salt Flats, where numerous land speed records have been achieved at annual races.

There are no buildings here and no roads.

Just about 50 square miles of salt flat, which, like now, is flooded for a good portion of the year, reflecting a huge sky and the surrounding mountains.

That doesn't stop people from getting out there anyway.

And tracks are visible throughout.

Traces of human intervention have been detectable throughout our epic Utah journey.

While at points you feel like you're alone out here, without a rest stop or cell service for miles, there are reminders everywhere, if you look for them, of what we're doing here and what we've done, on scales small and very, very large.