The Soo Locks

Right here at Sault Sainte Marie sits one of the most consequential pieces of infrastructure in North America, a place where the fate of American steel, iron, and automotive production rises and falls with each passing ship.

The problem the Soo Locks solved is simple but enormous. Lake Superior sits twenty-one feet higher than the other Great Lakes. For centuries, the only way to move goods past the St. Mary's River rapids was to portage around them, a seven-week ordeal. In eighteen fifty-three, Congress granted seven hundred fifty thousand acres of public land to any company willing to build a lock. The State of Michigan took the challenge, and in just two years workers carved two chambers three hundred fifty feet long out of the Michigan wilderness. The first ship through was the steamer Illinois, upbound on June eighteenth, eighteen fifty-five, with Captain Jack Wilson at the helm. That seven-week portage became a seven-minute transit.

The tonnage through the locks grew at a staggering pace. One million tons passed in eighteen seventy-six. Ten million tons by eighteen ninety-two. Over one hundred million tons in nineteen forty-one, the year the nation's war production machine ran at full throttle.

Today four locks operate here, but the most important by far is the Poe Lock, opened in nineteen sixty-eight and wide enough for the thousand-foot ore freighters that dominate Great Lakes shipping. Here is the national security problem: eighty-eight percent of domestically produced high-strength steel, the kind that goes into cars, appliances, and military equipment, rides through iron ore that can only fit through the Poe. A Department of Homeland Security study concluded that a six-month closure of the Poe Lock alone would shut down seventy-five percent of American integrated steel production, wipe out eighty percent of iron ore mining, and eliminate eleven million jobs. One lock. One chokepoint. Standing between a functioning industrial economy and something close to collapse.

Congress has been funding a second large lock since two thousand sixteen. When it opens, this narrow channel at the top of Michigan's mitten will finally have the redundancy the American economy has been missing for decades.