The adoption of state renewable portfolio standards (RPS) in Washington, Oregon, and Montana in the mid-2000s, combined with federal and state tax incentives and renewed opportunities for PURPA qualifying facilities, contributed to a significant increase in renewable resource development over the last two decades. Now, as tax incentives phase down and upcoming RPS targets are on track for compliance, a new policy movement is developing – decarbonization of the electricity system. States, utilities, and communities are passing aggressive clean energy targets and economy-wide greenhouse gas reduction goals that will influence the future resource build-out of the regional, western interconnect, and national power system.