Green River

About

Green River, Washington — 1862 Howard Hanson Dam 1962, 1911 Tacoma Diversion, Flaming Geyser 1971. Long before any of that, the Green River watershed was home to the Duwamish and Muckleshoot peoples, whose salmon runs were among the most productive in the Puget Sound basin. The Muckleshoot Indian Tribe retains treaty fishing rights from the 1855 Point Elliott Treaty and continues to manage salmon resources on the river. That deep continuity — people and salmon on the same water — underlies every chapter that follows.

The watershed's industrial history came in overlapping waves. From the 1830s through the 1920s the forests were logged to feed the regional timber industry and the railroad expansion of the 1860s onward, with local sawmills, logging drives, and downstream lumber operations as the major operators. Large-scale logging wound down after the 1910 exhaustion of the old-growth stands, the 1915 start of state forestry conservation, and the 1930s establishment of state forests. Overlapping the timber years, the 1850s–1910s coal mining era put the Green River coal mines to work supplying the Pacific Coast's coal market.

The river's hydrology drew scientific attention early. The USGS surveys of the 1870s–1890s, the gauging stations established from the 1880s onward, and later state geological streamflow assessments were the first comprehensive hydrological studies of the Green. Decades later, state water pollution control studies and Clean Water Act assessments took on more than a century of logging, agricultural, and industrial impacts, with modern restoration and TMDL programs the current outcome.

Then came the engineering that defined the modern river. The 1911 Tacoma Water Supply Diversion Dam and the Howard A. Hanson Dam — completed by the Corps of Engineers and serving as the headwaters of the Tacoma water supply — reshaped how the valley lived with its river. Built primarily for flood control and to supply water to Tacoma, the Hanson Dam finally tamed the valley below and opened it to development. Downstream, the river's lower section becomes the Duwamish, which engineers straightened and dredged in the early 1900s to feed Seattle's industrial ambitions, turning a meandering tidal channel into a working waterway. The 1990s–2010s brought the Howard A. Hanson Dam restoration project.

For paddlers, the Green divides into three sections. The Upper Green runs Class I–II from the Headworks to Kanaskat, a mountain run. The Green River Gorge, Kanaskat to Flaming Geyser, is the best section at Class II–III. Below Flaming Geyser, the Lower Green drops to Class I on an urban float into Auburn. Flaming Geyser State Park was established along the river in 1971, and King County's Green River Gorge Conservation Area — expanded by 2020 to protect over 1,500 acres of old-growth forest and sandstone canyon — puts wilderness-grade whitewater within reach of Seattle. The river runs on a USGS gauge (12113000) that averages about 1,600 CFS, and today it still supports the Auburn and Kent economies at the valley floor.