The Walla Walla County Public Works Department proposed to reconstruct a portion of Mill Creek Road in Walla Walla County. Mill Creek Road provides principle access to 100,000 acres of Umatilla National Forest, which contributes both recreational and logging resources. Mill Creek Road also provides access to residences, university and municipality facilities, and tourist activities.
As this is a federally funded project, the potential impacts to historic properties must be considered prior to implementation, as per Section 106 of the National Historic Preservation Act (NHPA). To that end, the County retained Plateau Archaeological Investigations (Plateau) to conduct the cultural resource survey.
Plateau archaeologists completed a pedestrian survey of the entire Project Area. Much of the proposed undertaking will be completed within the existing road alignment. However, two segments of the road will be shifted east to compensate replacing the Mill Creek Bridge and Klicker culvert.
The current Mill Creek Bridge was inventoried, and determined not potentially eligible for listing on the National Register of Historic Places. The bridge was constructed in 1958 and is now slated for replacement. At present, the structure is in a state of deterioration, has insufficient width, and has less than 4.0 feet of clearance between the bottom of the bridge structure and the stream bed.
Plateau excavated 41 shovel probes within the Project Area. One shovel probe, located in the realignment passing through an open field, contained a modified flake. Four additional shovel probes surrounding this positive probe provided no further evidence of Native American cultural materials or features. The artifact was recovered from the plow zone (15 cm below surface), suggesting a disturbed context in artifact location. The proposed undertaking will result in No Historic Properties Affected, and no further archaeological investigations was recommended prior to, or during, execution of this project.
Location: Walla Walla County, Washington