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Digging up the past under the Alaskan Way Viaduct
Seattle Times staff reporter
For scientist Charlie Hodges, even a speck of coal unearthed from Seattle's waterfront can be a tantalizing clue.
Hodges and other experts hired by the state are poring over geologic records, picking through core samples and studying 120-year-old maps — all in an effort to learn what may be buried near the Alaskan Way Viaduct.
The scientists are documenting the extensive man-made changes to the shoreline and looking for signs of archaeological finds, especially tribal artifacts or even Indian burials that might be exhumed if the viaduct is replaced by a new aerial roadway or tunnel.
Significant archaeological finds, especially tribal burials, can delay or even kill a construction project.
The state is still smarting from its surprising find in 2003 of Tse-whit-zen, an Indian village and burial ground in Port Angeles. Construction was under way to build a dry dock when some 335 intact Indian skeletons were unearthed at the shoreline site. The state walked away from the unfinished project in 2004, after spending nearly $90 million.
No one expects a find like Tse-whit-zen under the viaduct, said Kate Stenberg, the state's environmental manager for the viaduct-replacement project. But the department isn't taking any chances, either, on a highway project that could cost between $2.5 billion and $4 billion.
For more information about the
viaduct project, visit the state's
Web site at: www.wsdot.wa.gov/projects/viaduct
"We are planning ahead, to gather the story of this waterfront," Stenberg said. "We want the fullest, richest, broadest story, to see what material is left and what is significant."
The hunt for clues has been fruitful so far: Hodges was pleased when the piece of coal was dug up right where the old fire-insurance maps indicated a coal chute used to be.
"It's good to know our system is working," Hodges said.
Next month, contractors will drill a dozen test borings, some 180 feet deep, beginning at the intersection of Yesler Way and Columbia Street. Five-inch-diameter core samples will be extracted. That's big enough to pull up artifacts, along with layers of soil that will help tell the history of the ground.
The level of detective work on the viaduct and seawall-replacement project is without precedent for the state and goes far beyond the review conducted at the Port Angeles dry-dock site.
The Seattle waterfront is known to be rich in history. And the viaduct project is huge — at two miles long, it would be one of the largest public works projects on the West Coast.
Digging a tunnel poses the greatest risk of hitting archaeological deposits, but even a new elevated roadway could disturb Seattle's past. Giant new footings would be needed: Preliminary estimates say shafts may be as big as 14 feet wide and 150 feet deep.
The greatest chance of hitting archaeological finds is along the central waterfront and north, at the foot of Belltown, where the path of a new viaduct would cross Seattle's historic shoreline. To the south, the shoreline was substantially filled in over the years.
This same shore was home to American Indians for thousands of years, long before the Denny Party slogged ashore in 1851 at Alki Beach.
"There have been [Indian] burials found in the area in downtown Seattle in the past," said Leonard Forsman, chairman of the Suquamish Tribe and an archaeologist. "There are areas of high probability within Seattle that the tribes are concerned about."
Scientists also are combing through old Sanborn Company fire-insurance maps, which depict the floor plan of every building on the waterfront going back to 1867. Superimposing those maps on aerial photographs of the project area will help planners figure out what was built where.
That information will be matched with archaeological records from previous finds, as well as maps, photos and geological records.
Ultimately, experts want to build a 3-D model of the ground, showing where the native soil was, its composition and the layers of fill heaped on top. The modeling will show the alteration and development of the waterfront since the arrival of whites, documenting major historic events that shaped the city, from the Great Seattle Fire of 1889 to the Klondike Gold Rush of 1897-1898, and the extensive regrading and filling of the city and tide flats.
Understanding all the changes will be a challenge. Seattle's waterfront is a trickster, wily as the character of Raven in Indian lore. It's a landscape on which nothing is quite as it appears.
What looks like solid ground from about South Dearborn Street to South Spokane Street and east to Interstate 5 was once tidal flats. Fill dirt was heaped on it at depths of 100 feet in places, creating what is now Seattle's industrial belt.
"A lot of it is clean fill, gathered elsewhere," Stenberg said. "but we are still investigating it."
The area downtown near Seneca Street and heading north through Belltown is now flat land. But it was once hilly with ravines, a place where Indians lived and buried their dead. Much of the bluff was sluiced out in a series of radical regrades.
And the ancient shoreline moved too, in a massive earthquake some 1,100 years ago. It heaved up giant hunks of the beach line and sunk it in other locations. It all makes for surprises.
Workers constructing a sewer plant in Magnolia in 1992 found remains of an Indian settlement dating back at least 4,000 years — a find they never expected and attributed to the earthquake and changing sea levels.
Help from local tribes
By this fall, the state hopes to have assembled enough pieces of the puzzle to create a draft report that can be shared with local tribes.
Consultation with tribal leaders on the viaduct project has been under way since 2001. In the next round of meetings, planners hope to check the accuracy of their findings and fill in more blanks.
The department may even hire elders as expert reviewers, in coordination with tribal governments.
"They are that human tie with the past that is hard to get in any other way," said Megan White, Environmental Services office director for the state Department of Transportation. "People's memories capture more than what people write down."
Dennis Lewarch, an archaeologist for the Suquamish tribe, helped author a 2004 survey of tribal uses of what is now downtown's waterfront.
The study found the viaduct project potentially could disturb human remains and burials, with some finds potentially dating back as far as 2,000 years. The tribes built villages and seasonal camps on the shore, used the land for food processing and crafting such items as fish weirs, baskets and stone and bone tools.
"They are going to hit the historic beach, and that's where people were living," Lewarch said.
The department took a beating for perfunctory tribal consultation prior to the Port Angeles project. But this time, the department has been diligent, some tribal leaders say.
"I didn't want to meet with them, but boy, they were persistent," said Cecile Hansen, chairwoman of the Duwamish Tribe. "They never gave up. I have to commend them, they really wanted to know what we thought."
Forsman agreed the department is doing its homework. "So far, so good on the outreach. But we are still waiting to see how the process continues," Forsman said.
"We hope that for the most part that the excavations go as planned, and that we don't have disturbance of burials. And we'd like to avoid archaeological sites. But in a project this size, it is probably unavoidable that there will be some find."
Lynda V. Mapes: 206-464-2736 or firstname.lastname@example.org
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