In June, Tamara Thomsen and Mallory Dragt went diving on underwater scooters in Wisconsin’s Lake Mendota. Down 27 feet below the lake’s surface, the dive buddies came across something they first thought might be a log but turned out to be an extremely rare 1,200-year-old dugout canoe.

The 15-foot-long canoe was brought ashore later before a crowd of locals gathered on a beach to witness a small slice of history.

“This is the first time this thing has been out of the water in 1,200 years,” James Skibo, Wisconsin’s state archaeologist, tells the Wisconsin State Journal. “And maybe they left from this very beach to go fishing.”

Teams prepared for months to extricate the canoe but were careful to carry out the removal before it deteriorated much more or had a chance to be moved by shifting waters and before ice formed on the lake’s surface.

A week or so before the recovery, divers dredged around the canoe, then used rebar and rope to keep it in place on the lakebed. On the day the boat was brought to the surface, a crew gathered including a dive team from the Dane County Sheriff’s Office, photographers and videographers with the Wisconsin Historical Society, and a local volunteer diver who had much experience bringing up objects from the floor of Lake Michigan.

The divers used float bags to raise the canoe to the surface, then it was towed a mile to shore in a sling. The trip took over an hour, as the boat towing the canoe was careful not to go much faster than idling speed.

Once ashore, it was transported (with a police escort) in an enclosed trailer typically used by Wisconsin Department of Natural Resources wardens.

“It was a team effort,” Thomsen, who is also a maritime archaeologist for the Wisconsin Historical Society, tells the Journal. “I’m actually surprised at how smooth it went. You always expect for there to be problems and you anticipate the worst and hope for the best, but it came up faster than we thought. Everybody really danced together to make it come up.”

Archaeologists used carbon-14 dating to estimate the canoe was 1,200 years old, making it the oldest intact boat ever discovered in Wisconsin waters. It was likely exposed after a boat with a sizeable wake caused a sediment shift.

“Not only has it been underwater; it’s been under the ground,” Skibo says. “The reason it’s so well preserved is that it has not been exposed to the light. So that’s one of the reasons we have to start preserving it. [There are] living organisms on it that are chewing away on it as we speak.”

In order to prevent further degradation and make the boat more solid and stable, it will undergo a two-year series of preservation treatments. First, it’s being submerged in a tank at the State Archive Preservation Facility to preserve its liquid environment and kill any algae or microorganisms. Then, it will be treated with polyethylene glycol, which will replace the water that has saturated the wood.

Ultimately, the canoe will be displayed in the Wisconsin Historical Society.