Green River / Duwamish Waterway Fishing Report & Flow Guide

The Green River, transitioning into the Duwamish Waterway as it nears Puget Sound, is one of Western Washington’s most important and heavily-fished rivers. Originating in the Cascade Mountains and flowing through King County, the river’s health and flow are critical factors for anglers pursuing salmon and steelhead. Before planning your trip, always check the latest Washington river flow data to ensure safe and optimal fishing conditions.

River History and Flow Control

The modern Green River is a system profoundly altered by human engineering, primarily for flood control and water supply. Historically, the entire Green/Duwamish system was prone to devastating seasonal floods. The solution arrived with the construction of the Howard A. Hanson Dam (originally Eagle Gorge Dam) by the U.S. Army Corps of Engineers.

Completed in 1961, the Hanson Dam, located near the river’s headwaters, effectively ended the valley’s history of major flooding. However, this dam, along with the earlier, man-induced diversion of the White River and Cedar River, greatly reduced the Green River’s watershed and cut off access to significant amounts of headwater habitat. This management makes flow monitoring an essential part of fishing preparation.

Location and Access

The Green River flows through a varied landscape, offering different fishing experiences across its length. The headwaters are protected wilderness, but the navigable, fishable sections begin downstream of the major dams. The stretch flowing near Auburn and Kent is heavily channeled and easily accessible. As the river passes Tukwila and approaches Seattle’s Elliott Bay, it becomes the Duwamish Waterway, where tidal influence creates unique and highly productive fisheries, particularly for Salmon.

Primary Species and Seasonal Runs (Salmon & Steelhead)

The Green River remains a premier hatchery river, supporting healthy runs of multiple salmon species and a population of winter steelhead. The fish are critical to the local ecosystem and the reserved treaty rights of the Muckleshoot Indian Tribe.

Fish Run Timing:

• Fall Chinook Salmon: The run begins in earnest in August, with fish entering the tidal sections. Peak fishing often runs through September and early October, especially in the lower river and Duwamish sections.
• Pink Salmon (Humpies): The Green River experiences massive, staggered returns of Pink Salmon exclusively on odd-numbered years (e.g., 2025, 2027). The run typically peaks in August and September, providing a high-volume fishery.
• Coho Salmon: The Coho run begins in September and continues through November. Fish move quickly into the river, often staging near the mouth of Soos Creek, home to the Green River Hatchery. A later spawning stock sometimes allows for a run extension into December and January.
• Chum Salmon: Known for their aggressive nature and ample size, the Chum run hits its peak in November and continues through much of December. This late-season run offers excellent fishing when other salmon runs have tapered off.
• Winter Steelhead: The primary Steelhead return occurs throughout the winter, typically peaking between January and March. Anglers target these challenging fish in the middle and upper river stretches.

Regulations and Conservation

Conservation of the Green River's wild Chinook population remains a high priority, which often results in restrictive and complex regulations. Anglers must pay close attention to boundary changes, gear restrictions (such as anti-snagging rules), and species retention limits that change annually.

For the most current rules, seasons, and any emergency closures specific to the Green River and Duwamish Waterway, always check the official resources from the Washington Department of Fish and Wildlife (WDFW).

WDFW Fishing Rules: Consult the latest WDFW Fishing Regulations.