Ashland will have to hire an archaeologist to study whether a redesign of the Plaza would threaten artifacts buried nearby before construction can proceed.
Once it has the archaeologist's report in hand, the Oregon State Historic Preservation Office will determine which areas of the redesign might threaten artifacts and what the city should do to recover them or make sure they're not disturbed, said Dennis Griffin, state archaeologist for the historic preservation office.
The city will be required to dig small test pits in some areas and deeper test pits in others to help the SHPO determine whether artifacts are present within the project area, he said.
"Other portions of the project will probably only require a professional archaeologist to monitor ground-disturbing activities," Griffin said. "An archaeologist now will assist the city in determining where which strategy will work the best."
The city is searching for an archaeologist to conduct the survey, said city planner Amy Gunter.
"We will be waiting to find out what an archaeologist discerns from the documents we have collected "… the state will let us know what needs to be done," she said.
The cost of the archaeological work has not been determined, said Scott Fleury, the city's project supervisor.
"It seems like overkill for what we plan to do," said City Administrator Dave Kanner. "Of course we will comply with whatever SHPO asks of us "… but does this mean we have to contract with an archaeologist every time we replace a sidewalk, dig a utility trench, or replace a tree in the downtown area?"
Before the state issued its recent decision, Kanner said he doubted a survey of the site for traces of American Indian and settler artifacts would be required, because most of the original topsoil there has been covered by several feet of fill dirt since Ashland was settled in the mid-1800s.
"I don't think we will be disturbing anything," he said.
There are known archaeological sites that could be affected by the redesign work and specifically the planned tree removal, which would extend to a depth of about three feet, Griffin said.
Two archaeological surveys have been conducted along Ashland Creek upstream from the Plaza, and uncovered large quantities of Native American and settler artifacts, said Mark Tveskov, Southern Oregon University associate professor of anthropology and director of SOU's anthropology laboratory.
In 2002, Tveskov led a limited survey along the creek that uncovered remnants of an ancient fireplace, a glass bead, arrow heads, pieces of stone tool and several chips of worked stone, he said. That work was intermingled with the city's effort to extend a utility trench of Winburn Way.
Another unofficial survey was conducted in the 1980s on the grassy area at the entrance to Lithia Park, but was never finalized in an official report, Tveskov said.
That dig, where the former Ashland Flour Mill stood, was led by then SOU professors Nan Hannon and Rich Olmo and revealed hundreds of Native American and settler artifacts, Tveskov said.
Tveskov said he is not familiar with the intricacies of the Ashland Plaza redesign or its proposed impact, and he is uncertain whether the project warrants a similar survey.
The redesign calls for removing several large trees on the Plaza that are suffering from ground compaction above their root systems. They will be replaced with tree species more suited to tight urban environments.
The estimated cost to carry out the Plaza redesign is $170,000. The city plans to use lodging tax revenues set aside for downtown improvements and economic development.
"Our office looks forward to working with them as they move forward toward development of their project," Griffin said.
Officials typically don't reveal the exact location of defined archaeological sites, because people have been prone to looting them.
Reach reporter Sam Wheeler at 541-499-1470 or email firstname.lastname@example.org.