Archaeological dig at former Blue Heron site yields precious — and historic — findings

SUBMITTED PHOTO: CLACKAMAS HISTORICAL SOCIETY - The Oregon City Woolen Mill as seen in 1874. Heading into a recent dig at the former Blue Heron Paper Mill property in Oregon City, archaeologist Rick Minor had a vague idea of what he might find buried in the soil.

He knew there would be plenty of artifacts from the late 19th century, when the Oregon City Woolen Mill was constructed and the area around the Willamette Falls became heavily industrialized. Far more enticing, in Minor’s eyes, was the prospect of finding even older historic artifacts buried deep beneath the surface — undisturbed for perhaps thousands of years.

Now that would be truly special.

The dig took place over the course of two weeks in August 2015 and was sponsored by a grant from the State Historic Preservation Office as well as the current property owner, Falls Legacy, LLC. Minor, a senior archaeologist and co-founder of Heritage Research Associates, was joined by a number of fellow archeologists as well as volunteers from the Oregon Archeological Society (OAS).

SUBMITTED PHOTO: WILLAMETTE FALLS LEGACY PROJECT - Archaeologist Elaine Dorset working in a trench on the first day of the dig back in August 2015.

The dig site was located at the heart of the 23-acre former Blue Heron property adjacent to downtown Oregon City, which is set to be dramatically reimagined as part of the Willamette Falls Legacy Project. On the heels of a $7.5 million commitment from the State Legislature back in July 2015, planning is under way for one of the project’s centerpieces: a riverwalk that will offer unprecedented public access to the river and scenic Willamette Falls.

On Jan. 19, Minor presented his preliminary findings at a “Pints from the Past” event hosted by the Clackamas County Historical Society and the Oregon City Public Library. While the final report won’t be issued until later this spring, Minor is comfortable calling the dig a success.

“Working with a volunteer crew and only being there 10 days, we were able to accomplish quite a bit,” Minor said in an interview with the Tidings. “We gained a lot of new knowledge that we didn’t know before.”

In the early stages of the dig, the findings were very much in line with what Minor anticipated.

“We immediately started recovering late 19th century artifacts, like we were supposed to,” he said. “They dated back before the north mill (was constructed), back in 1890.”

As the archaeologists dug deeper, they came upon what Minor called “a hard layer of compact fill.”

SUBMITTED PHOTO: WILLAMETTE FALLS LEGACY PROJECT - Volunteers search through the excavated soil in a trench.

“We thought that was the underlying bedrock at first,” Minor said. “But we kept digging and came upon this intact native soil, about 60 centimeters thick, that then goes down and hits bedrock.”

That native soil was the white whale Minor had hoped to find when he first signed on for the dig. It contained a number of Native American artifacts, and Minor said radiocarbon dating marked it as about 1,500 years old.

“It’s not unexpected in that we know Native Americans are all over the falls,” he said. “But we didn’t know they’d be on that property, because of all the historic development.

“That was really cool.”

For Christina Robertson-Gardiner, a senior planner with Oregon City, the dig was a rare chance to explore a property without the pressure of a concurrent development application.

“We had an opportunity to do a proactive archeological investigation that was not tied to development,” Robertson-Gardiner said. “And that’s really special.”

Minor added that the archaeologists were particularly lucky given how much flooding had occurred in the site’s past.

“Flooding removes sediments, so between floods and development, there was doubt if we’d get any archeological materials at all,” Minor said. “I know it doesn’t sound very exciting, but that we had an intact hardpan layer that separated more recent historic materials, and below it the historic deposit — that was exciting from an archeological point of view.”


Learn more about the dig and the Willamette Falls Legacy Project at

Patrick Malee can be reached at 503-636-1281 Ext. 106 or This email address is being protected from spambots. You need JavaScript enabled to view it..

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