tl;dr: Nonprofit-built artificial beaver dams on tributaries of California's Scott River restored ~9,000 m² of cold, slow-moving wetland habitat, boosting juvenile coho salmon survival from 8% to 60%. Salmon returns to the Scott River remained strong even during drought, outperforming other monitored rivers. Researchers say the low-cost interventions demonstrate beavers' ecological value, but long-term recovery depends on landowners tolerating actual beaver populations.