Howard A. Hanson Dam

Howard A. Hanson Dam is an embankment dam crossing Eagle Gorge that rises above the Green River and uses a concrete spillway to manage water flow. The structure holds water across a drainage basin and helps regulate downstream conditions throughout the year.

Construction began in 1959 with an explosive blast and finished ahead of schedule in 1961. The project was designed to address recurring flood problems that threatened the valley.

The dam transformed the Green River Valley from flood-prone farmlands into a developed area with warehouses, industrial facilities, and residential communities.

The area around the dam is open to visitors with various viewpoints to observe the structure and water behind it. Comfortable shoes are recommended since pathways can be uneven and weather conditions near the river can change quickly.

The structure prevented approximately 694 million dollars in flood damage by 1996 through its advanced water management system.

Location: King County

GPS coordinates: 47.27780,-121.78700

Latest update: December 10, 2025 20:07