Every now and then, a treasure would come out of the earth at Fort Snelling that stopped the archaeologists in their tracks.

This one, lost long ago in the grass near the old barracks, resurfaced during renovations for the new visitor center.

A button.

A button from a World War II soldier's uniform, by the look of it.

"Everyone just stopped what they were doing," said Jennifer Rankin, director of archaeology at the Minnesota Historical Society, whose teams had shadowed construction crews around the site for months as work on Historic Fort Snelling's newest addition unearthed clues about its past.

The archaeologists gathered around the find, wanting a closer look.

"We all had to check the artifact out," Rankin said. "Because everybody had family members that served in World War II. I think that was a connection that brought all of us together."

Nothing connects you with history like holding a piece of it in your hand.

History is everywhere at Fort Snelling, and this weekend, archaeologists are bringing it close enough to touch.

Saturday is Archaeology Day at Fort Snelling. Visitors can watch archaeologists at work at a dig site under the fort's floorboards, take in a flint knapping demonstration or help clean, analyze and research new finds.

For 10,000 years or more, humans have lived, worshipped, traded and fought on this land. They all left their mark. Stone projectile points, copper tools, cannon balls. Ghostly outlines in the earth of hearth fires, fortifications, stables, slave quarters, a Dakota War concentration camp, a World War I hospital. All layered one atop another.

Rankin and her crew finished fieldwork around the new visitor center in July. They collected the artifacts, then carefully reburied the other features for future archaeologists to explore. Now they need to fit the objects they found into the story of this place.

There's a curled bugle insignia that tumbled off a soldier's hat sometime around the Civil War. There are foundation lines that might mark the barracks where the 25th Infantry — the segregated regiment known as the Buffalo Soldiers — might have garrisoned when they served at Fort Snelling in the 1880s. There is a biface point, possibly a multiuse tool, knapped from chert. They found it beneath the roadway near the visitor center, which was also a roadway thousands of years ago when the tool was lost.

Not everyone makes it into the history books. Each object the Minnesota Historical Society pulls from the earth is a chance to tell someone's story. A World War II soldier who lost a button. A long-ago traveler who lost a tool.

"There's a lot in the historical record that isn't documented, and that's why archaeology is so critical," Rankin said. "We can present stories that aren't told. At the fort, there are a lot of stories that haven't been told."

Archaeology Day at Historic Fort Snelling will run from 10 a.m. to 3 p.m. Saturday. For more information, and many more stories, visit mnhs.org/fortsnelling.

jennifer.brooks@startribune.com • 612-673-4008

Follow Jennifer on Twitter: @stribrooks