- Recent growing interest in reducing greenhouse gas (GHG) emissions requires the application of effective energy solutions, such as the utilization of renewable resources. Biomass represents a promising renewable resource for bioenergy, since it has the potential to reduce GHG emissions from various industry sectors. In spite of the potential benefits, biomass is limited due to logistical challenges of collection and transport to bio-refineries. This study proposes a forest biomass-to-bio-oil mixed supply chain network to reduce the GHG emissions compared to a conventional bioenergy supply chain. The mixed supply chain includes mixed-mode bio-refineries and mixed-pathway transportation. Life cycle assessment is conducted for a case study in the Pacific Northwest with the assistance of available life cycle inventory data for biomass-to-bio-oil supply chain. Impact assessment, on a global warming potential (GWP) basis, is conducted with the assistance of databases within SimaPro 8 software. Sensitivity analysis for the case investigated indicates that using the mixed supply chain can reduce GHG emissions by 2–5% compared to the traditional supply chain.