Olympia-Grand Coulee Transmission Line

Olympia-Grand Coulee Transmission Line

The Bonneville Power Administration proposes to replace worn insulators and improve associated access roads along a segment of the Olympia — Grand Coulee 287 kV Transmission Line in Kittitas, Chelan, Douglas, and Grant counties of central Washington. Plateau was retained to conduct the cultural resource survey to identify potential archaeological resources and potential historic properties prior to proposed construction and maintenance of the necessary access roads and landing areas.

The pre-field research revealed 180 previously recorded cultural resources within one mile of the Project Area; 11, of which, are within 550 feet of the Project Area.

Plateau archaeologists conducted pedestrian survey that covered the entire area of potential effect, and placed 63 subsurface probes where possible, based on surface conditions and the location of subsurface utilities. No pre-contact or historic-era cultural materials or features were identified during the subsurface probing, but during the pedestrian survey the archaeologists identified three sites; a pre-contact rock feature and two historic debris scatters. In addition, two isolated finds were identified during the pedestrian survey, a historic-era glass vessel and a precontact lithic flake. Plateau recommended that one site is eligible for inclusion in the National Register of Historic Places. The site falls outside of the delineated Project Area; however, due to close proximity to equipment transportation and staging areas the site could potentially be impacted and, thus, should be avoided. Plateau also recommended that all ground-disturbing activities should occur under the guidance of an Inadvertent Discovery Plan. In the event that cultural materials are encountered during implementation of this project, the Inadvertent Discovery Plan provides appropriate protocols and procedures to follow in accordance with state and federal laws.