The site was discovered in 1987, when the Utility District trenched the area to install a sewer line. When the excavation reached a depth of approximately 5 m below the surface, workers encountered huge bones - but did not report them. At the day's end, some of the workers took home some of the bones. Fortunately, one of the city officials, plus a teacher from the High School, observed the removal of the bones and were able to obtain a few of specimens for analysis.
In 1996, investigations of the site were initiated through the Center for the Study of the First Americans at Oregon State University. Under the CSFA umbrella, researchers and scientists from the Institute for Archaeological Studies and the Department of Geosciences at the University of Oregon began testing the site, to determine stratigraphic integrity and to locate other megafauna deposits. During week-long investigations in June and August, 1996, it became apparent that the preservation at this site was unparalleled for this late Ice Age time. Further, a remarkable microfauna record was identified. Woodburn provided the first documentation of numerous species of small, Ice Age animals in the Pacific Northwest.
The preservation at Woodburn allowed for the availability of many organic samples. Plant macrofossils present within these samples include mostly riparian woodland species -- alder, spirea, dogwood, birch, and lots of emergent aquatics. Abundant wood is present, providing radiocarbon ages for the site ranging from 10,300 to 12,300 years.