The authorities at the Port of Seattle got a phone call from a concerned citizen one day this summer. Was there a submarine lurking under the pier jutting out into the Duwamish River in Jack Block Park? No, came the reply, that's just art. But in some ways, the caller was right. The art along the Duwamish this summer is bringing up what's under the murk.

The caller hadn't seen anything—it was sound that made him convinced a sub was down there. Robb Kunz and Joshua Kohl are the artists. Sometimes the sound, which plays underfoot, is an otherworldly groaning, rhyming with the great rusty tugs parked at the beach nearby, where signs warn against swimming or eating the fish. Kunz had to brave high tide five separate times to get the art there because he had to lash the speakers to the underside of the pier. He did it by canoe, waiting for the right moment when he could stand tall enough to attach the speakers but not be crushed between water and wood.

At the same time, the Shell oil rig bound for drilling in Alaska was parked in sight, right around the bend in the water, and fleets of kayaking protesters would glide by Kunz at all hours. The place was so charged that it hardly seemed odd when one day Kunz heard a lone voice yelling for help. Somehow, a man had tumbled into the river. Rescuers pulled him out, hypothermic. He seemed to Kunz unstable. When night came, Kunz watched the blast furnaces of the nearby smelter turn the sky red.

It's not just the quality of the sound composition that makes the art ominous, it is the quality of the air and the water. It's the only place in Seattle where nobody swims.

But what is true about the Duwamish will also be false; it is an inestimable, complex character. It is polluted and it is glorious. In a city defined by water stories, the Duwamish River is the best water story we have. The views that accompany the sound art on the pier are not only of the imperiled and bedraggled waterway but also of otters, eagles, and herons, bucolic woods and crisp Puget Sound, and the best views of the city's skyline from a lovely, idolizing distance. The river also bears, unmistakably, the presence of the first people, and a different time.

On the bike trail down to the pier, a curve opens onto a view of industrial Terminal 5, where Shell's rig was parked on its wretched mission. Next to the bike trail, an official orange traffic sign reads "CRITICAL REFLECTIVE DISCOURSE-FREE ZONE," as if government signs routinely say such things. That sign is a work of art by Jack Daws, another Seattle artist. The port approved the artwork, helped Daws plant it in the port's ground. Shortly thereafter, they notified him it had been stolen.

When Daws reported the theft to port police, they had to admit, sheepishly, that they had it in custody. It hadn't been stolen, it had been confiscated by police who misunderstood it as a protest sign. (Which it sort of was. The artist made it before the protests, but he was thrilled when he could place it in front of the visiting rig.) Apologizing, the port put the sign back up, but Daws noticed the police had damaged it en route, so the port gave Daws the money to make a new one. Plenty of critical reflective discourse might be had about all this.

Daws's signs—there are two others—and the sound art on the pier are part of a onetime happening this summer. It's called Duwamish Revealed, involving 100 or so artists and dozens of installations and performances, and it comes at exactly the right time. In December, the EPA released its $342 million plan to clean up the river, which was declared a Superfund site in 2001. Earlier this month, the federal government once again denied the plea of the Duwamish Tribe to be recognized. Just as Seattle would not be Seattle without the Duwamish Tribe, there would be no city here without the Duwamish River. So attention must be paid.

The organizers of Duwamish Revealed are an urban planner, Sarah Kavage, and a landscape architect, Nicole Kistler. They're working with the tribes, the port, the city, and the county, and under the umbrella of the Environmental Coalition of South Seattle. A couple years ago, Kavage and Kistler created their own smaller tribute to the Duwamish. It was a full-scale barge like the ones that regularly pass these waters piled with scrap metal, but this one was planted as a living garden that grew as they sent it along the river.

Extending that tradition, one of the artists in this year's Duwamish Revealed planted a sculpture made of live cuttings of willow on the river's edge at Terminal 107 Park. The plants form the shape of a container ship, and will grow.

"It's not that we don't want the container ship or we don't want the industry—it's just that we have to balance all these things," James Rasmussen told me, describing why he likes Briar Bates's mixing of worlds in willow.

Rasmussen is director of the Duwamish River Cleanup Coalition and a descendant of Dr. Jack, the Duwamish medicine man who rowed the meandering S curves of the river making house calls before the river was widened, straightened, and used as a dumping ground in order to establish industry and the city itself.

Meg Hartwig scaled the old Georgetown Steam Plant pump house on the banks and painted the chimney bright bloody red. On the walls behind the red line, she painted calm green S curves. At the end of her installation, she will have to turn the whole building back to gray, erasing her binary map of the history. Two white buoys bob in the water next to Hartwig's spot, but when the tide is low, the black on their lower halves is visible. On top of each one, there's a tall chair fashioned from a metal ladder. The empty chairs face each other on the water, waiting for dialogue. Or they might be mistaken for regular maritime equipment. They're art by Buster Simpson. This little park, officially called Gateway Park North, is across a gravel road from Boeing. People live out here; you can see the tents. When the river is cleaned up, where will those people go? For now, the rough place is nicknamed Anarchy Point.

There are dozens of little pocket parks like this one along the river, most barely known by anyone. Herring's House Park is on the other side of Marginal Way from the Duwamish Longhouse. A mounted skeleton of a fishing boat is on display, with an old official sign that quietly explains that development had to be halted there in the 1970s when digging turned up remains of Native living. Today, lone men cruising each other walk the forested park, where paths disappear into unwalkable thickets. A peaceful grove of trees is in the care of artist Roldy Aguero Ablao, who is indigenous to Guam and gay himself. Up high on the tree trunks, he's wrapped delicate white paper chains and twists. They wear down, but he returns to the park to nurse them in rituals where he involves other Native people in wishing long-term love on this place and its people.

Dances, music, canoe families making their arrival on the banks—all of these are part of Duwamish Revealed. You probably can't see it all. One piece is deliberately out of view: Anne Blackburn hid tiny surveillance cameras at Hamm Creek, where wildlife "share" their lives day and night on Blackburn's Instagram feed.

Another sign by Daws sits at a quiet segment of water's edge down the river a ways from Jack Block Park. The sign is wood rather than metal, and it points along the river past a bunch of beached, barnacled tires. Trees rise up on both sides of this stretch of banks, pretty. But where the water bends and disappears, right where the sign points, a huddle of unmarked concrete silos rises into the summer sky. It's some kind of factory; there are many here, with names like Portland Cement and Chemithon. The sign practically spits the sarcastic words "THE NEW WORLD," but in letters that are the honey-yellow font used for mile markers in the wilds of national parks.

New worlds don't come much older than this one. recommended