Opinion editor's note: Editorials represent the opinions of the Star Tribune Editorial Board, which operates independently from the newsroom.

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The U.S. Army Corps of Engineers is asking for the public's help in determining the future of the Mississippi River in Minneapolis. One intriguing insight into the river's possible future lies in its past.

The river we know today is very different from the one that sustained Native people for thousands of years before Minneapolis was founded. An English visitor in 1766 noted the profusion of eagles' nests on Spirit Island, which once lay just below St. Anthony Falls. One might still spot eagles along the river today, even in downtown Minneapolis. But in those days downtown did not exist, and the river was wild.

And from St. Anthony to what would become Fort Snelling, the river was an impressive stretch of whitewater rapids.

It's hard to imagine now, thanks to the sedative effect of the locks and dams that have made the river navigable. Acting at the direction of Congress, the Army Corps of Engineers built Lock and Dam No. 1 in 1917; that's the installation just downstream from the Ford Parkway bridge in St. Paul. Then came the Lower St. Anthony Falls Lock and Dam in 1956 and the Upper St. Anthony Lock and Dam in 1963. With that, the Mississippi in Minneapolis went from a wild, sometimes roaring river to a domesticated one, with perhaps two dozen species of fish instead of more than 100.

Seven years ago on these pages, writers Steve Berg and Ron Way described their vision of a restored Mississippi River from downtown to Fort Snelling. "With boulders and islands uncovered, the river's 100-foot drop between downtown Minneapolis and Fort Snelling would create a gushing spectacle during times of high water," they wrote. "These rapids would be a kayaking paradise and a sporting delight. Scores of eagles would soar overhead, drawn by all the fish that would mass in the oxygen-rich water and spawn in gravel beds under the swirling eddies."

Other major cities have rivers, they wrote, "But no one else has rapids."

Now that vision has a chance of becoming reality. The Upper St. Anthony Lock was closed by order of Congress in 2015. With its mission to facilitate commercial navigation concluded, the Army Corps no longer has a compelling reason to keep operating the other locks and dams.

So the Corps has begun a painstaking process of coming up with a recommended course of action. It's seeking public comment as part of that process. The Corps is working to determine whether there's a continuing federal interest in keeping the locks and dams in operation; whether it should transfer them to some other agency, and whether the better course is to remove them or leave them where they are.

The first, essential step is to conduct studies to answer a multitude of questions, among them: What are the potential environmental effects of removing the locks and dams? What would happen to the hydropower plants operating along the river? Would the removal of two dams weaken the river's defenses against invasive carp? Would bridges and retaining walls need to be rebuilt or reinforced? How might accumulated tons of river sediment be managed to keep from flushing it down the river? How much would all this cost, and where would the funds come from?

Answers will take time. An Army Corps fact sheet says it won't be ready to make a recommendation to Congress until 2024 at the earliest. If the Corps decides to recommend removal, and Congress agrees, the work itself will be a major project. Paddlers who dream of shooting the rapids from downtown Minneapolis to Minnehaha Creek will have to be patient.

Such changes always come slowly, John Anfinson, author, historian and former superintendent of the Mississippi National River and Recreation Area, told an editorial writer.

"Every lock and dam, every refuge, every levee, every flood-control measure on the Mississippi River has been done because a group of people wanted it to happen and they were persistent in making it happen," he said. "Sometimes it took decades. And that's the opportunity here."

He added, though, that doing nothing is not an option. "The world is changing. We can't keep what we had. Navigation's gone, the Corps wants to go away. So what's the new world going to look like?"

The Army Corps of Engineers will hold its fourth and final open house on the topic from 6 to 8 p.m. on Oct. 25 at Dowling Elementary in Minneapolis.