Riffe Lake

Riffe Lake
Name	Riffe Lake
Location	Lewis County, Washington, United States
Type	Reservoir
Inflow	Cowlitz River
Outflow	Cowlitz River
Basin countries	United States
Area	2,800 acres (11 km²)
Max-depth	200 ft (61 m)
Elevation	571 ft (174 m)
Created	1968
Dam	Mossyrock Dam

Riffe Lake is a reservoir in Lewis County, Washington formed by impoundment of the Cowlitz River behind Mossyrock Dam. The impoundment created a freshwater lake that altered local Cowlitz Indian Tribe territories, inundated communities such as Randle, Washington adjunct valleys, and became integral to hydroelectricity production via Puget Sound Energy. The lake sits within the Gifford Pinchot National Forest region and lies downstream of Mount St. Helens.

Description and Geography

Riffe Lake occupies a valley carved by the Cowlitz River and tributaries including the Tilton River and Clear Fork Cowlitz River, extending into canyons near Packwood, Washington and the townships adjacent to Salkum, Washington. The reservoir spans shorelines downstream of Mossyrock Dam and above flood control structures tied to the Cowlitz Falls Project and regional Columbia River basin operations. Surrounding landforms include slopes of the Cascade Range foothills and drainage into the Toutle River watershed; nearby protected areas include parts of the Mount Rainier National Park and federal lands managed by the United States Forest Service. Access roads connect to state routes such as Washington State Route 12 and roads toward Morton, Washington and Eatonville, Washington.

History and Construction

Construction of the dam that created the reservoir was undertaken by Army Corps of Engineers-related contractors working with Mossyrock Dam proponents and Puget Sound Energy in the mid-20th century, following regional power planning influenced by Bonneville Power Administration studies and postwar infrastructure programs. The project required negotiation with the Washington State Legislature and relocation of residents from inundated places including former settlements and agricultural lands near Randle, Washington and Kosmos, Washington; property transfers involved entities such as Lewis County, Washington authorities and private landowners. The reservoir reached full pool following completion of impoundment in the late 1960s, altering transportation corridors including bridges on routes connected to U.S. Route 12 and prompting archaeological surveys in consultation with the Cowlitz Indian Tribe and Department of the Interior.

Hydrology and Ecology

The reservoir regulates flows in the Cowlitz River system and interacts with downstream projects like the Hydroelectric Project at Cowlitz Falls and fish passage operations coordinated with the National Marine Fisheries Service and Washington Department of Fish and Wildlife. Water levels affect habitat for anadromous species migrating to the Columbia River and broader Pacific Northwest salmon runs involving Chinook salmon, Coho salmon, and Steelhead. Terrestrial ecosystems around the lake include mixed conifer stands dominated by species found in the Pacific Northwest, providing habitat for mammals such as black bear, elk, and avian fauna including bald eagles monitored by the U.S. Fish and Wildlife Service. Limnological studies have been conducted by institutions including University of Washington and Washington State University researchers, addressing water quality parameters, sedimentation from tributaries like the Tilton River, and invasive species management informed by Environmental Protection Agency guidelines.

Recreation and Access

The reservoir supports recreational activities managed by county and state agencies including Washington State Parks and Recreation Commission facilities and local outfitters from towns like Packwood, Washington and Morton, Washington. Popular uses include boating, angling for species monitored under Washington Department of Fish and Wildlife regulations, camping near Forest Service campgrounds, and hunting in adjacent public lands. Access points connect via county roads to Washington State Route 12 and local marinas; recreational safety and navigation notices are coordinated with Puget Sound Energy and emergency services such as the Lewis County Sheriff's Office and Washington State Patrol.

Environmental and Safety Issues

Reservoir operations have raised concerns addressed by agencies including the United States Geological Survey and National Oceanic and Atmospheric Administration concerning seismic risks in the Cascade Range and potential impacts from Mount St. Helens eruptions observed during the 1980s. Public safety incidents and submerged hazards prompted surveys and cautionary measures overseen by Puget Sound Energy and regulatory reviews by the Washington Utilities and Transportation Commission. Environmental mitigation efforts have been coordinated with tribal governments like the Cowlitz Indian Tribe and federal bodies including the Environmental Protection Agency to manage water quality, sediment control, and fish habitat restoration programs tied to regional Endangered Species Act considerations.

Cultural and Economic Impact

The reservoir reshaped livelihoods in Lewis County, Washington and surrounding towns such as Randle, Washington and Eatonville, Washington by supporting hydroelectric power generation for utilities including Puget Sound Energy and contributing to regional energy grids overseen by entities like the Bonneville Power Administration. Cultural implications involved displacement negotiations with the Cowlitz Indian Tribe and archaeological assessments by the State Historic Preservation Office and academic institutions such as Evergreen State College. Tourism tied to boating and angling has economic links to businesses in Packwood, Washington, lodging operators, and outdoor recreation outfitters, while resource management intersects with state agencies like the Washington Department of Natural Resources and conservation organizations including The Nature Conservancy.

Category:Lakes of Washington (state) Category:Reservoirs in Washington (state) Category:Lewis County, Washington