For more than 30 years, researchers have scoured the depths of Lake Superior for vessels lost to time. Each carries a dramatic story of lives at risk and, many times, lives lost. A stretch of shoreline in Michigan with about 200 known shipwrecks is called “Graveyard of the Great Lakes.”

Among the greatest of those mysteries has been the disappearance of a fleet belonging to the Edward Hines Lumber Company. On Nov. 18, 1914, the steamboat C.F. Curtis was towing two schooner barges and carrying three million board feet of lumber when a surprise storm sent all three boats to the bottom of Lake Superior. Twenty-eight crew members died across the Curtis and the two schooners, the Selden E. Marvin and the Annie M. Peterson.

Now, more than 100 years later, researchers with the Great Lakes Shipwreck Historical Society say part of the mystery of where the boats laid has been solved.

The historical society in Michigan’s Upper Peninsula announced last week that it had found two of the fleet’s three boats during exploratory missions with its research vessel. The Curtis was found in the summer of 2021, some 500 feet below the surface along with eight other shipwrecks, and the Selden E. Marvin was found the next summer, about 600 feet below.

“When the robot went down, as soon as they hit it, we saw the age on the smokestack, and we knew it was the Hines fleet,” said Ric Mixter, a maritime historian and a board member of the historical society’s museum. “We could actually read the paint” of the Edward Hines Lumber logo on the Curtis, he said.

The two boats were discovered about 25 miles off the shore of Grand Marais, Mich., about four to five miles from each other. The museum hopes the third boat, the Annie M. Peterson, will be found next.

“It’s exciting to find something that changes history a little bit,” Mr. Mixter said, “but it’s also sad because it is a gravesite for 28 people.”

Finding the Curtis and the Marvin was equal parts luck and dedication.

The Curtis, Marvin and Peterson are just three of about 6,000 vessels believed to be shipwrecked in the Great Lakes. Every summer, the historical society’s 50-foot research boat trawls the waters off the coast of Whitefish Point to look for sunken ships, even searching through heavily trafficked active shipping lanes among passing freights as large as 1,000 feet.

The Curtis and the Marvin were found near the area known as the “Graveyard of the Great Lakes,” largely because of a combination of factors that include shipping congestion and bad weather. The discovery is considered to be among the group’s greatest.

Because there were no survivors from the three ships and reports (including two brief mentions in The New York Times) about the wrecks varied, researchers have had to piece together a record of what exactly happened on that November day. Historians know that the boats were part of the Hines fleet — the largest lumber fleet on the Great Lakes at the time, with eight steamers and 11 barges in all — and that the three boats were en route to Tonawanda, N.Y., with enough lumber to build 1,200 houses.

They also know that other boats in the Hines fleet had experienced bad weather in the days leading up to the sinking of the Curtis, Marvin and Peterson. But the forecast for that day, Mr. Mixter said, did not lead to any concerns.

After exploring the two ships, the museum researchers believe the Curtis was towing the Marvin in second position and the Peterson in the third.

“We see a good portion of her stern is ripped off, and we can tell by the towing bits that she was probably in the middle of the tow,” Mr. Mixter said of the Marvin. “It just surprised us to see the damage on the front and the back of that ship.”

Mr. Mixter said it appeared that the storm “snapped” the tow line between the Curtis and the Marvin.

“It went down so quickly that nobody had a chance,” Mr. Mixter said.

Under the lake, Mr. Mixter and a team from the museum were able to see history in granular detail: axes to cut lines if there was a problem, a hand-cranked grinding wheel, a piece of a shirt around rope, tow ropes that clearly snapped.

“To me, that makes it more of a place where men lived, a place where men worked and tragically a place where men and women have been lost,” he said. Unlocking a mystery that “has captivated the lakes, but in many ways faded away since 1914,” Mr. Mixter said, “it’s just so powerful.”

Still, there is the mystery of the Peterson to solve, and the historical society’s research boat will revisit the area where the Curtis and Marvin were found this summer.

“I’m hoping that the Peterson is going to be relatively close,” Bruce Lynn, the executive director of the museum, said. “We have searched in those areas, but it’s just never easy. Often they’re in places you’re not expecting.”

The researchers also hope to find relatives of those who were lost at sea. No one has come forward so far, but with renewed attention around the findings, Mr. Lynn said he wouldn’t be surprised if that changed.

“We do search for these wrecks, and when we’re fortunate — when we’re lucky to find them — it helps us keep the memory alive of the ships, of those sailors, male and female, that were onboard those ships, and keep those stories alive,” Mr. Lynn said. “It’s a little bit of history that kind of gets hidden. It’s under water — nobody thinks about it.”