A plaster cast of a footprint, estimated to be about 800 years old, unearthed at The Forks in Winnipeg. (Wendy Sawatzky/CBC)

An archeological dig at the site of the future Canadian Museum for Human Rights in Winnipeg has unearthed a rare find: a footprint estimated to be 800 years old.

For the past few weeks, archaeologists have been scraping away at the future site of the Canadian Museum for Human Rights at The Forks, where the Red and Assiniboine rivers meet in central Winnipeg. The area has a rich history that includes aboriginal camping, the fur trade, the construction of the railway, waves of immigration and the Industrial Age.

Thousands of artifacts have been uncovered, including pottery and arrowheads. But a footprint is an unusual find, says chief archaeologist Sid Kroeker, due to the complicated series of events that must take place in order for it to be preserved.

"They stepped down and their foot pressed into the clay, left a footprint and either the ground dried out and hardened, or it froze," he said.

"The next flood episode that came through put down a slightly different type of sediment, so that the two soils didn't meld together and obliterate it."

It's not clear if the footprint was made by a man or a woman, but it was probably left in the mud around 1200 A.D., Kroeker said. Pieces of pottery and fish remains were found underneath it, he said.

The area appears to have been a popular campsite around the time the footprint was left, he said.

"Somebody was camped there, a group of people. By the style of pottery, they were from eastern Manitoba. But they were also being visited by another style of pottery, people from western Manitoba," he said.

"The two groups were sitting there, probably fishing because bison and venison are very lean meats so you need the fat from catfish to round out your diet."

The finds won't interrupt the construction of the museum, Kroeker said, noting that archaeologists are essentially digging the building's basement. The dig is in compliance with provincial and federal heritage site legislation and was always part of the construction plan for the museum.

The dig is scheduled to continue for the rest of the summer and will extend about three metres under the surface of what used to be a parking lot. The footprint was found about two metres below the surface.

The Forks site is one of the top 10 archaeological sites in North America, Kroeker said.