Puget Sound Energy (PSE) contracted HRA to conduct cultural resources investigations for the proposed stabilization of the Upper Baker Dam spillway slope in Whatcom County, Washington. The spillway slope was at risk of failure, and its stabilization would enable PSE to return the power generation capabilities of the dam to previous levels. HRA provided cultural resources services for the project in compliance with the Baker River Hydroelectric Project’s Federal Energy Regulatory Commission (FERC) License and Baker River Hydroelectric Project Historic Properties Management Plan (HPMP). HRA identified a historic-period dam, powerhouse, and pipeline that were previously determined to be contributing resources to the National Register of Historic Places (NRHP)-eligible Baker River Hydroelectrical Development Historic District in the project’s area of potential effects. HRA recommended that the project would have a negligible impact on these resources and no “adverse effect” on the Baker River Hydroelectric Development Historic District’s NRHP eligibility.