Construction crews in Edmonton have found evidence of the city’s first settlement, believed to date back to 1802.

What construction crews thought was just a trench is now being considered the discovery of the city’s first fur trading fort, under the city’s Rossdale Power Plant.

Archeologists digging at the site discovered what is believed to be the remains of a trading post’s outer stockade wall trench.

The discovery was made underneath the concrete floor of the power plant’s demolished machine shop, a few hundred metres from where a known burial ground was previously found on the Rossdale Power Plant property.

“It’s actually one of the earliest non-native structures in the entire city,” says senior archeologist Nancy Saxberg.

“There was more than one fur trade site on the property but I think we have found the earliest one,” Saxberg says.

Saxberg and her team conducted digs on the site between May and June. During that time, crews also found an aboriginal stone pipe with a zigzag pattern etched into it, a possible sign that it was used by Canada’s Blackfoot tribe.

Saxberg admits they haven’t found a lot of evidence of aboriginal occupation earlier than the fur trade in the area.

“They had to have been camping somewhere in the area. What attracted them? I’m not really sure,” Saxberg added.

It’s not clear when experts will start studying the artifacts.

The utility company that owns the power plant plans to build new offices on the site.

With files from CTV Edmonton’s David Ewasuk