This benefit-cost analysis investigated Southeast Washington's Lower Snake River dams, modeling the regional economic benefits in the form of outdoor recreation expenditures that are expected to accompany a free-flowing river. The dams yield a benefit-cost ration of only 0.15, but a free-flowing Lower Snake River may yield a ratio of over 4.3. In a dam breach scenario, outdoor recreation could generate as much as $500 million in consumer expenditures in the first few years alone.