The Confederated Tribes of Grand Ronde on Thursday announced it had finalized its purchase of the Blue Heron Mill site in Oregon City, which sits next to the landmark Willamette Falls.

The tribe said it had entered into an agreement with the Oregon Department of Environmental Quality to clean up the site and that the work would begin shortly.

Long-term commercial redevelopment plans for the site, or parts of it, remain unclear. Tribal officials have said they aren’t considering building a casino on the site, but haven’t said much else other than the environmental work is their first priority.

“There will be parts of this property that will be redeveloped, but we have a lot of work that needs to happen before we get there,” said Grand Ronde spokeswoman Sara Thompson. “This is part of our ancestral homeland, and our ancestors had a responsibility to take care of this place. Part of our responsibility is to take on that role.”

Cleanup work will include the removal of on-site hazardous waste, leaking underground storage tanks, contaminated soil and asbestos materials in a mill office building.

The site will also provide access to the river for ceremonial fishing, a cultural keystone. “This property assures that tribal members will be able to access Willamette Falls for a cultural purpose,” Thompson said.

The tribe didn’t disclose the purchase price, and the sale hadn’t yet been entered in Clackamas County property records Thursday afternoon. The seller, Washington state developer George Heidgerken, paid $2.2 million for the site in 2014, and the county assessor values it at $2.9 million.

Grand Ronde also said the $35 million Willamette Falls Riverwalk Project would proceed to allow closer public access to the falls by repurposing one of the former mill buildings. Plans call for that phase of the project — a partnership between Oregon City, Clackamas County, the Metro regional government and the Willamette Falls Trust — to begin next year and open in 2022.

The Blue Heron Paper Mill closed in 2011, more than 100 years after the Hawley Pulp and Paper mill opened along Willamette Falls. It had been used for industry since 1829. Before that, tribes had fished and traded on the site for millennia.

-- Elliot Njus

enjus@oregonian.com; 503-294-5034; @enjus

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