Purpose of Review <p>The Bonneville Power Administration (BPA) provides a unique window into how long-standing public agencies adapt to rapidly evolving governance challenges in the energy transition. This paper traces BPA’s institutional evolution from its New Deal origins to its current role in climate mitigation, market integration, and ecological stewardship, with attention to how policy feedback and institutional layering shape its adaptability.</p> Recent Findings <p>BPA’s historical trajectory demonstrates how agencies can persist through crises not by abandoning their core mandates but by reinterpreting them under new conditions. The Northwest Power Act of 1980 codified this adaptive process, embedding environmental and participatory obligations alongside economic efficiency. More recently, BPA has faced bottlenecks around transmission interconnection, permitting under legacy environmental statutes, and the need to integrate with regional electricity markets. These challenges highlight the institutional contradictions of pursuing decarbonization within frameworks designed for ecological protection and democratic accountability.</p> Summary <p>The paper concludes that BPA shows how established public agencies can evolve under constraint, adapting their practices to meet diverse and competing demands. Its experience underscores the importance of procedural innovation and coalition–building for maintaining legitimacy in governing shared infrastruscture under climate imperatives.</p>