Fifty empty, lidless wood coffins and a possible human leg bone have been found buried in the ground along Arlington Avenue in Duluth in the last week.

The coffins and alleged human bone were unearthed on the east side of Arlington Avenue just south of Arrowhead Road during a planned archaeological exploratory dig for an upcoming St. Louis County road project in the area, the county announced on Monday. The items are assumed to be remnants left behind during a 1960s grave relocation project involving nearby Greenwood Cemetery, where about 5,000 people from the St. Louis County Poor Farm were buried from 1891 to 1947.

“We didn’t expect to find the coffins, but we did, and once we found them, we kind of realized why they were there and why they were empty,” said county resident engineer Steve Krasaway.

The crew working on the excavation are digging down to the coffins, but aren’t digging the coffins out. Instead, a team of archaeologists will sift through the dirt in and around the coffins in the coming weeks to determine whether there are any other human remains, Krasaway said.

The county has also notified the Fond du Lac Band of Lake Superior Chippewa and the Minnesota Indian Affairs Council about the discovery of the bone because some of the people buried in Greenwood Cemetery were of Native American ancestry, according to the county.

The area has been fenced off and the county is advising people to stay out of the excavation site for both safety reasons and out of respect for any potential other remains that may still be there.

The county didn’t find any coffins or bones earlier this year when it completed a survey of the area using radar and digging by hand. However, the county wanted to go a step further with an excavation to confirm the earlier results, which isn’t typically done in a road project, Krasaway said. It’s “a high area of concern” for potentially finding human remains in the ground during the road project due to its close proximity to Greenwood Cemetery, he explained.

The road project, which includes reconstructing and widening Rice Lake Road north of Arrowhead Road, isn’t scheduled to begin until 2020. But the county began the archaeological work early to give staff time to properly address anything that it finds, he said.

“This is all done in front proactively so that when we have a multimillion dollar road reconstruction project occuring in 2020, that we didn’t run into any unknowns at that time. Now we can just deal with things properly and take our time and do it right and meet with the correct people and notify correct people and organizations. These are real human remains that we need to treat with respect and do the proper thing to make sure they get relocated to the right spot,” Krasaway said.

So far, they’ve only located one bone in the excavation, which will be tested to confirm that it’s a human bone. The project was put on hold when the bone was found on Wednesday. County staff met on Friday with the state archaeologist and Minnesota Indian Affairs Council to discuss the discovery. The coffins found so far are lidless and empty, but if a coffin with a lid containing a full set of human remains is found, they’ll stop the excavation again to follow the correct process, Krasaway said. The coffins are leading everyone involved to agree that they were likely part of the 1960s grave relocation project in the area, he said.

When Arlington Avenue was widened in the 1960s, remains from more than 100 bodies were taken out of their coffins and put into a mass grave in another part of Greenwood Cemetery. The St. Louis County Board declared Greenwood Cemetery inactive in 2012 - meaning it will remain undisturbed and in its current condition - since recordkeeping was often inaccurate at the turn of the century. The county found numerous unmarked graves, duplicate grave numbers and general confusion over where particular people were buried.

County staff began talking a year ago with local historians and archaeologists who knew the area because of the history of it, Krasaway said. The county has been working with local archaeologist Susan Mulholland, president and principal investigator with Duluth Archaeology Center, to research the possibility of graves in the area and she’s been on site during the excavation in the past week.

“By being proactive and getting out ahead of time will really help pay off to make sure we do things properly with these remains and help get the road project done without any hiccups,” Krasaway said.