Groups join to bring unique experience to Tualatins visitors

In the midst of peak vacation months, Tualatin is still on track to offer an unusual kind of travel experience: Ice Age Tourism.

This goes beyond the mastodon bones on display at the public library, as grants approved last year to the city and Chamber of Commerce give Tualatin a chance to shine as a point of geologic and prehistoric interest.

As president of the Lower Columbia Chapter of the Ice Age Floods Institute, Rick Thompson explains, Tualatin is located along a route as significant as the Lewis and Clark Trail: the Ice Age Floods Trail.

“Tualatin was sort of a crossroads in a way,” said Thompson.

explaining that the Ice Age floods — which happened an estimated 15,000 years ago — occurred when an ice dam in the Idaho panhandle broke, causing the 500 cubic mile Lake Missoula to empty over a period of two days. (The size of the lake is comparable to two of the smaller Great Lakes.) The water flowed from Idaho through Washington and the Gorge, coming through the Tualatin Valley by way of Lake Oswego. From there, the lake flowed to the Willamette Valley through what is known as the Tonquin Scablands, so named because of how harshly the topsoil was scoured in the process of the flooding. This extreme overflow was so intense that water reached depths of about 400 feet in Tualatin, and 350 feet as far south as Eugene.

Why is this significant?

Partly because, according to Tualatin Heritage Center board member Yvonne Addington, this displacement of minerals explains why Willamette Valley has such fertile soil and unique agriculture. The ice dam itself broke into glaciers, which carried with them rocks and minerals that would end up in Tualatin. Many of these “erratics” — or non-indigenous rock formations — are being collected by the Tualatin Heritage Center.

“Those rocks are what we find in the Willamette Valley, telling us how deep (water) was and where it went,” Thompson said.

This region is significant not only to geologists, but to the federal government as well. The Omnibus Public Land Management Act of 2009 designated the Ice Age flood path between Missoula, Mont., and the Pacific Ocean as part of the National Wild and Scenic Rivers System. But because of a lack of funding, Thompson said, it falls to cities like Tualatin, and organizations like the Tualatin Heritage Center, to create comprehensive materials and exhibits that draw attention to the area’s rich geological heritage.

Former Tualatin Heritage Center president Addington remains a board member, tracing her passion for Tualatin’s Ice Age history back to 1962, when she helped then-Portland State University student John George type up his thesis. This was the man who discovered and excavated mastodon bones in a swamp just south of Fred Meyer. As Tualatin City Manager in 1974, Addington recalls being shocked to discover the mastodon skeletal remains on display at PSU, because they were errantly labeled the “Tigard mastodon.” She corrected the mistake at PSU, and years later, a professor offered the bones to her when space became an issue. Possession of the bones was circuitous (Addington gave them to the Oregon Zoo for a time), and eventually she reclaimed them, working with a citizens’ group to raise money and properly erect the skeleton as it still stands in the Tualatin Public Library.

Addington’s interest in prehistory stayed with her, and she remains actively involved in collecting the remains of not only prehistoric fauna, but also erratics, like a 10-ton piece of granite the THC recently acquired.

“Just before the end of my presidency in 2011, we were alerted that there were Ice Age erratics — there was a boulder that came down here in an iceberg,” said Addington. “We got a call from Gaston Farms and found a granite erratic and a quartzite erratic that both came from Missoula, Montana.”

With the help of the Clopton Excavating Company, Addington was able to bring the specimens to the THC.

“We found them at elevation 228 feet above sea level, and the only way they could get there was to be floated in on an iceberg,” Addington said. She explained that granite is not generally found in the region.

By that point, Addington and the historical society were well into the process of creating an “Ice Age visitors plan,” which had branched out of the THC’s request for a grant from the Washington County Visitors Association.

“We formed a joint committee, city, chamber, historical society partnership,” said Addington. “We’re all trying to find something for the people to see and understand for the educational process.”