The Fort St. Joseph archaeology open house promises to be a mix of Monty Python interspersed with a colonial militia muster reminiscent of the eve of the American Revolution.

The sixth annual event, which, in the past, has brought an estimated 10,000 people to Niles, will be held from 10 a.m. to 4 p.m. Saturday and Sunday at South Riverfront Park, near the intersection of Fort and Bond streets.

This free event showcases 2012 findings of Western Michigan University’s annual dig.

Barbara Schwaderer and Bob Myers previewed the open house, which features an 18th century encampment by the Northwest Territory Alliance. Eighty re-enactors will stage a militia muster.

Re-enactors portray the king’s 8th Regiment of Foot, the only military unit in the region in 1775.

For the re-enactors, it is the timing that throws in the Monty Python twist.

“Setting it in 1775 is later than we frequently portray,” Schwaderer said. “We’ll have 18th century skills shown, merchants selling reproduction goods, a Celtic trio.”

The trio, Moxie Strings with Fritz McGirr, was formerly String Cheese consisting of fiddler Diana Ladio and cellist Alison Lynn, who appear Fridays at Fiddler’s Hearth in South Bend.

“We’ll have a women’s sewing circle,” Schwaderer said.

Period children’s games will add another perspective to the timeline.

“We’ll have a tea tent for refreshments. The other new thing this year is Sarett Nature Center’s 35-foot Montreal canoes offering rides for $3 for half an hour so people get an idea what it was like on the river. There will be competitions in the encampment, such as tomahawk throwing.”

Fort St. Joseph was one of a handful of Michigan sites to play a role in the American Revolution. Virginia troops under George Rogers Clark captured Fort Sackville in present-day Vincennes, Ind., in 1779, then planned an assault on Detroit.

Knowing Clark’s force would pass near Fort St. Joseph, the British at Michilimackinac planned an ambush. British regulars, French militia and hundreds of allied Native Americans gathered at the fort to attack the Virginians, but lack of supplies thwarted Clark’s plans. British troops returned to Michilimackinac.

Niles’ fort was one of the most important colonial outposts in the western Great Lakes.

The mission, garrison and trading post complex was occupied from 1691 to 1781 and under the control of four nations, giving rise to the “City of Four Flags.”