The color red — the color of blood, of an imagined antediluvian ocean — figured prominently in the conception of Robert Smithson’s “Spiral Jetty” (1970), a monumental artwork located at the edge of the Great Salt Lake, and the poster child of the Land art movement. “On the slopes of Rozel Point I closed my eyes, and the sun burned crimson through the lids,” Smithson wrote in 1972. “I opened them and the Great Salt Lake was bleeding scarlet streaks.”

Indeed, the artwork is situated in a part of the lake where the water, or at least what remains of it, is reddish — or pinkish, or purplish, or orangeish, depending on the conditions at the time of one’s visit — due to an array of halophilic microorganisms that thrive in high-salt environments. To Smithson, the pigmentation evoked the primordial seas.

Color isn’t the only visible way the lake responds to environmental stimuli. The Great Salt Lake is a terminal basin, meaning that it has no output; it’s served by four major tributaries and changes mainly according to cycles of precipitation and evaporation. Terminal lakes are expected to rise and fall. After Smithson’s completion of “Spiral Jetty,” the work was submerged and notoriously remained invisible for over two decades. When I visited its home, Rozel Point peninsula, in the early spring of 2010, the water had completely receded from the spiral, leaving the sculpture’s black basalt rocks encrusted in crystals of white salt — a visual contrast Smithson had anticipated with the lake’s fluctuations.

Those fluctuations, however, are increasingly fewer and farther between: it seems that Smithson’s primordial sea is drying up. Last November, NASA’s Earth Observatory blog published satellite photographs of the Great Salt Lake from 2011 and 2016, revealing a significant shrinkage of its boundaries. Comparing a Google Earth screengrab of “Spiral Jetty” taken by Hyperallergic in 2014 to one today shows a similarly dramatic movement of the shoreline away from the sculpture.

“In the recorded history of the lake, we’ve never seen drought as this level. The lake is now at a historic low,” says Bonnie Baxter, the director of the Great Salt Lake Institute in Salt Lake City, Utah. One of the factors affecting lake level, Baxter tells me, is upstream water demand. The Great Salt Lake is located at the bottom of a watershed, and water upstream has increasingly been diverted to serve developments and agriculture, leaving little to flow into the isolated north arm of the lake, where “Spiral Jetty” is located.

The other factor is more sinister and directly related to climate change. Baxter explains that the western United States is experiencing the onset of what’s called a “megadrought,” citing a 2015 NASA study published in the journal Science Advances. “We don’t anticipate water back to the lake. We don’t anticipate more precipitation in the future. We anticipate that this drought is a permanent fixture and is likely going to get worse,” she says. “And that’s based on data.”

As a result, the lake is expected to get saltier and saltier. The news might sound auspicious for the salt-loving bacteria, algae, and archaea that are responsible for Smithson’s treasured hue — but the fact remains that the lake is desiccating at an alarming rate. Baxter expects the waterline to continue to recede, and for “Spiral Jetty” to one day become completely marooned in salt.

I asked Kelly Kivland, a curator at Dia Art Foundation, which owns “Spiral Jetty,” what this means for the artist’s vision. The idea of entropy, the principle whereby ordered systems become exponentially more chaotic, was a key tenet of Smithson’s work. It’s easy to imagine that he expected “Spiral Jetty” would encounter environmental factors beyond his control, and Kivland echoes this sentiment. “Our decision has always been to not touch the site, and to understand that he understood that the climate is part of entropy,” Kivland says, noting that Dia has had extensive conversations with the Smithson estate to inform their treatment of the artwork. Dia’s main priorities, she explains, are to maintain accessibility to the site, to continue to document the work through aerial photography, and to initiate further conversations about the changes impacting the area.

Smithson’s 1972 “The Spiral Jetty” essay concludes with a wordy pontification of crimson history, referencing blood, arteries, “a flaming chromosphere,” “raw meat with gristle,” and a mirage of van Gogh painting on “some sun-baked lagoon.” The artist’s fixation on the redness, on the otherworldly quality of the landscape, is palpable. According to Baxter, the halophiles around the jetty can survive for some time after the lake dries up, and thus, pinkish hues will remain in the salt for a period after desiccation. Smithson’s atavistic narrative will continue to play out. Eventually, it will all fade to white, bleached by the sun.