NEWPORT – Tyler Levesque, 6 – turning 7 on Friday – learned to swim last summer by boating across Sebasticook Lake with his family and swimming at a small beach at the northeast shore.

Tyler used a swim mask and had a great time diving down for rocks. “Look at this one, Dad,” he would call over and over. But one rock looked just a little bit different and although Tyler’s dad didn’t think it was special, Tyler did.

“I knew that it was special right away,” he said Wednesday night. “It had like a hole in it.” Tyler showed it to his mom and she also felt it wasn’t just any old rock.

It turned out that Tyler’s hunch was correct. An archaeologist with the University of Maine identified Tyler’s rock as a gouge, once used by Native Americans to shape the posts in a 6,000-year-old fish weir in Sebasticook Lake.

In 1992, the fish weir, or fish trap, was formally identified and dated by the late Dr. James Peterson of the University of Maine at Farmington as having been installed by Native Americans as a method of catching fish.

It is considered an extremely rare site, the oldest and best-preserved of its type in North America.

The Sebasticook fish weir was dated back to at least 3100 B.C. There are only three other known ancient weirs in Canada and the United States, but the Sebasticook site is distinguished not just for being the oldest, but also for being the most perfectly preserved.

The weir was created by gouging out small trees and saplings, pounding the posts into the bottom of the lake where the river entered, and then weaving branches through to create a net fence.

The weir allowed water to run through but trapped fish headed downstream. During most of the year, the weir is invisible under the lake but each fall, Sebasticook Lake is emptied to flush algae and phosphorus downstream and the weir appears. A bid to fund a dam to protect the weir was cut from the 2003 Maine Historic Preservation state budget.

Wednesday night, Tyler was honored by members of the Newport Historical Society after he presented the gouge to the group.

“This is part of one of the most important things in Newport,” Newport Historical Society President Ron Hopkins said, turning the stone gouge over in his hands. “We can’t thank you enough, Tyler.”

Hopkins said the gouge, along with casts made of the fish weir posts, will go on display in the Newport Cultural Center, which will likely be constructed next year to house both the town’s public library and the historical society’s impressive collection of artifacts and objects.

Gil Levesque, Tyler’s father, said the family frequently swam in the area where the stone object was found. When the gouge was found, Levesque said his wife, Bonnie, immediately said the item likely had historical significance. He said it was his son’s idea to donate the gouge.

Hopkins said that Dr. Brian Robinson of the University of Maine identified the object this summer. “He took one look at it and without even turning it over, said it was 6,000 to 7,000 years old. Older than the pyramids.”