] NA RRATOR: You're out in the world, exploring a part of the immensely varied landscape of our dear planet Earth, freed from your desk or whatever in life chains you.

You marvel at the beauty, the grandeur, the unfathomable immensity of it all.

You reflect on humankind's ability to control the landscape and dramatically fail to control it.

It's a multi-sensory experience, being in the outdoors, with visual input, of course, but also with plenty to hear, touch, taste, and beyond.

Our world has dimensionality, and it's always changing, too.

Why, oh why anyone feel the urge, the hubris to put art out here?

What kind of an art can thrive in the presence of such a formidable costar as Earth?

This is the case for land art.

We tend to think of art as primarily belonging to the indoor realm, to museums, galleries, to our homes, and places we congregate.

Sure, there are murals and sculptures here and there, but even when art is outside, it's still framed, bolted to a pedestal or a concrete slab, perched next to a fancy building, or nestled within a manicured sculpture park drafting, off the reputation of the institution to which it's tethered.

This framing helps divide these objects from the other, lesser objects that surround you and tell you that what you're looking at is special, authentic, rare, and valuable.

Beginning in the late 1960s, an increasing number of artists started questioning this kind of separation and framing of art, leaving the city and making stuff out in the world.

Sometimes it involved putting new material out into the world, like Robert Smithson's temporary mirror displacements, and sometimes it entailed taking material away, like Michael Heizer's immense excisions from a Nevada mesa.

Some of the projects were monumental and long lasting, like James Turrell's ongoing Roden Crater, and other times light and ephemeral, like Richard Long's A Line Made by Walking, where he walked back and forth across a meadow, drawing in his way a line of flattened grass.

People started to call these things earth art, earthworks, environmental art, or land art, catchall terms for a wide range of activities that were not an organized movement but were certainly a noticeable tendency.

We're going to call it land art, and we'll define it as art that is made within or atop or involving a landscape, or art that is made from materials drawn from the landscape.

Yeah, yeah, yeah, all art is technically made from natural materials, but we have to work from somewhere.

Let's just agree that it's a spectrum, and this is more land art than say, this.

But there's a lot in between.

And of course, humans have been making dramatic marks on the landscape since prehistoric times.

Across cultures and centuries, people have made highly site specific gestures, drawing lines, building mounds, and erecting massive geometric earthworks.

But just as each of these stem from vastly different motivations, the artists who made land art since the 60s have done so with specific and differing approaches.

It's said that a visit to the pre-Columbian Great Serpent Mound in Ohio inspired Robert Smithson's best known work, Spiral Jetty.

In 1970, he and two assistants moved nearly 7000 tons of earth, basalts, and boulders into the form you see here, projecting into Utah's Great Salt Lake.

It became submerged in 1972 and stayed that way until drought caused it to reemerge 30 years later, but that's precisely what attracted him to the site.

Drawn to the concept of entropy, Smithson explored in this work and others the reality that an artwork is never fixed and experiences decay from the moment it's made.

He also theorized the relationship between a site out in the world and what happens in an art gallery.

In a series he called Nonsites, Smithson brought materials like rocks from a specific place into a gallery and put them into shaped bins, positioning them next to a wall map indicating where the material originated.

For Smithson, the site was that natural location, and the non-site was its reprocessed, contained state in the gallery.

So in other words, and using examples Smithson never did, actual Yosemite Valley in California would be a site, and then Albert Bierstadt's 1865 painting, Looking Down Yosemite Valley, California, is the nonsite.

Smithson wrote, "the relation of a Nonsite to the Site is also like that of language to the world.

It is a signifier and the site is that which is signified."

Many artists at the time were trying to escape these terms and break free from the museum or gallery.

Making work out in and with the landscape was a way to do just that.

Nancy Holt's sun tunnels in Northwestern Utah stemmed from her motivation to allow visitors a way to experience the vastness of the land while also meeting the human desire for containment.

Four concrete tunnels are arranged in an open X, aligned with the rising and setting of the sun on the summer and winter solstices.

Holes pierced through the tunnels represent the stars of four constellations, to provide a sense of connection to the universe and also allow light to filter through and create changing patterns and shadows throughout the day.

Holt's work, and that of many working in the landscape, depend heavily on photography, film, and video to document it in its various unchanging states, and also allow people to see it who can't get to it.

Sometimes, the documentation was the work, as in the land interventions of Ana Mendieta, whose haunting Silueta series saw her inscribing female forms, sometimes hers, into a range of natural sites.

She created her marks and then photographed them or filmed them on Super 8, with only herself or a handful of others as witness.

The way the body moves through space was of great concern to many land artists, who often blurred the boundaries between art and architecture.

In 1979, art historian Rosalind Krauss wrote an essay trying to make sense or at least begin to of land art, as it relates to the category of sculpture.

Whereas modernist sculpture, which had its origins in the tradition of the monument, could maybe once be seen as the thing that was not landscape and not architecture, with all this wacky new installation and land art at the time, perhaps sculpture would now be better understood as being part of a structureless diagram or an expanded field that she proposed might look like.

This is pretty impossible to parse, but that's kind of what she was getting at, working to complicate and break up the firmly divided categories for art that had ruled the day up until then.

Art in a gallery was isolated from the outside world, which in the 1960s and 70s was rife with conflict.

The Vietnam War, the Civil Rights and Black Power movements and Second Wave Feminism were easier to forget within the white cube.

As art critic Barbara Rose wrote in 1969, "a dissatisfaction with the current social and political system results in an unwillingness to produce commodities which gratify and perpetuate that system.

Here the sphere of ethics and aesthetics merge."

The 70s saw the birth of the modern environmental movement, and land artworks also addressed a number of ecological concerns, not just out in the desert, but firmly in civilization, as well.

For his work Time Landscape, Alan Sonfist replanted an abandoned rubble strewn lot in Manhattan with plants indigenous to the island, recreating what might have existed there before it was settled.

The work sought to connect urbanites to their city's natural heritage and bring light to the seemingly runaway train of development.

It's still there, by the way.

Agnes Denes cleared the rubble from a landfill further downtown, planted a two acre wheat field, maintained it for four months, and harvested a yield of healthy wheat just blocks from Wall Street and the World Trade Center.

The work took place on hugely valuable land, and called attention to the choices we make in managing and mismanaging our resources.

Land art opened up a whole new way of working with place, kicking off a trend in art that remains strong of paying attention to the particularities of a site, its geology, its ownership, its histories, its present.

Whether in a dense city or out in the middle of nowhere, everything everywhere is site specific, and land art strips away those framing mechanisms to help us realize that.

The best of land art makes it impossible to forget where you are and sets into relief your surroundings with a clarity that jolts you out of the one thing after anotherness of everyday life.

Land art at its best helps us map our location in the world, and in time.

It's often inconvenient, and it cannot be rushed.

It must be walk through and around, and revisited at different times of day and in varying weather.

But in this, the age of the Anthropocene, in which we acknowledge the extent to which humans are actors on the natural systems of our planet, it's land art that is perhaps best suited to help us contemplate our complicated relationship with nature.

Are we part of nature or separate from it?

Do we make nature or does it make us?

What is the right way to live here on Earth?

What kinds of structures and places and systems do we want to build?

What is conquest and what is cultivation?