How Seattle sacrificed an ancient forest to power the Pacific Northwest

Ross Dam’s Drowning of 340 Million Board Feet

The Skagit Gorge once held a secret world of giants. Ancient Douglas firs, hemlocks, and cedars stood tall for centuries until Seattle needed power.

In 1937, work began on Ross Dam with $3 million from the feds.

As the dam grew taller between 1940 and 1954, water slowly swallowed 340 million board feet of pristine forest. The Decco-Walton Logging Company tried to save what they could, but in the end, less than 10% was rescued.

Today, North Cascades National Park visitors gaze at Ross Lake, unaware of the drowned forest still standing in its depths.

Money From Washington Helped Seattle Start a Forest-Flooding Dam

Seattle City Light got $3 million from the federal government in 1937 to start clearing trees from Ruby Basin. They planned to build Ruby Dam in four stages, with the first two creating a 305-foot dam.

The site sat in Skagit Gorge, home to an untouched old forest with about 340 million board feet of timber.

Engineers picked this spot 100 miles northeast of Seattle because the gorge narrowed, making it perfect for a dam that would flood the entire forest upstream.

Old Trees Couldn’t Compete With Progress

The canyon held a pristine forest of Douglas Fir, Western Hemlock and Western Redcedar trees that grew untouched for hundreds of years.

These giants had lived through countless winters in one of the last untouched old-growth areas in the North Cascades.

The rough terrain created huge problems for builders, with mountains rising 5,000 feet from the canyon floor. But the narrow spot in the gorge looked too good for engineers wanting to make a massive lake.

A Dead Boss Got His Name On The Flooded Forest

Workers started the dam in 1937 at the Rip Raps site just below Ruby Creek.

James Delmage Ross ran Seattle City Light’s Skagit Hydroelectric Project for years but died in March 1939 during construction. After his death, city officials changed the name from Ruby Dam to Ross Dam to honor him.

Crews kept working despite tough mountain conditions and weather that often slowed progress in this remote part of Washington.

Water Started Covering Trees As Early As 1940

By 1940, workers finished the first two building phases, making a 305-foot dam that raised water levels to 1,380 feet above sea level.

As Ross Lake formed behind the concrete wall, it began drowning the lower parts of the old forest. The dam’s first job wasn’t even making electricity – it just stored water.

Those old trees at the bottom of the gorge became the first victims of a flooding project that would eventually claim nearly all of the forest.

War Created Urgent Need For Power And Timber Rescue

World War II factories in Seattle needed more electricity, so the dam project moved faster.

In 1945, the Decco-Walton Logging Company formed with a contract from Seattle City Light to cut down trees before they went underwater. The loggers raced against time as water levels kept rising year after year.

Their job seemed impossible – save as much valuable old-growth timber as possible while the lake steadily grew beneath them.

Hoover Dam Builders Joined The Forest-Drowning Team

Construction sped up with help from Morrison-Knudsen, the same company that built Hoover Dam. The Federal Power Commission approved Step Three construction in 1947.

Workers finished this phase by 1949, bringing the dam to its final height of 540 feet. This taller dam meant water would back up even further, pushing Ross Lake across the U.S. -Canada border and flooding even more of the ancient forest.

Loggers Floated Timber To Canada As Waters Rose

Decco-Walton crews cut trees and floated the logs up the growing Ross Lake to British Columbia. From there, they hauled the timber to the Fraser River for processing and selling.

The rescue teams worked frantically as water kept rising throughout the late 1940s.

Moving logs from a flooding valley through an international border required complex planning between American and Canadian operations, all while the ancient forest slowly vanished underwater.

Canada Lost Land But Got Paid For Flooded Wilderness

Ross Lake reached the Canadian border in 1954, pushing water three miles into British Columbia.

Seattle City Light agreed to pay the Canadian government $250,000 for flooding 5,475 acres plus $5,000 every year after that. The cross-border flooding created a need for special agreements between the U.S. and Canada to manage the environmental impacts.

Neither country seemed particularly concerned about the ancient forest being lost forever beneath the rising waters.

Only A Tiny Fraction Of Ancient Trees Escaped The Flood

When Ross Lake filled completely in 1954, the Decco-Walton operation had saved just 30 million board feet of timber.

That meant less than 10 percent of the original 340 million board feet of ancient trees made it out of the valley. The other 310 million board feet of centuries-old forest disappeared forever under the reservoir.

The logging company simply couldn’t cut and move trees fast enough to beat the rising water levels that eventually stretched 24 miles through the former forest.

Hundreds Of Millions Of Board Feet Vanished Underwater

The 310 million board feet of timber left behind ranks as one of the largest deliberate floodings of old-growth forest in American history.

The irreplaceable ancient forest corridor that had thrived for centuries simply ceased to exist. Back in the 1930s and 1940s, nobody gave much thought to the environmental impact of drowning so many old trees.

The forest that once filled the Skagit Gorge became nothing more than a memory as water covered everything.

Seattle Powers Homes With Electricity From A Drowned Forest

Ross Dam now supplies about 20 percent of Seattle’s electrical power through four massive turbines. The entire Skagit River Hydroelectric Project cost $250 million over 50 years of construction.

People later started questioning whether drowning such a massive ancient forest was worth the power generated.

The project shows how Americans once valued engineering progress far more than preserving wilderness areas, a mindset that changed dramatically in later decades as environmental awareness grew.

Visiting North Cascades National Park, Washington

You can learn about the massive flooding that drowned 340 million board feet of old growth forest at Ross Lake by visiting the Ross Dam Trailhead at milepost 134 on Highway 20.

The 1.5-mile trail drops 500 feet to the dam where Seattle City Light flooded pristine wilderness between 1940-1954. There’s no park entrance fee.

Check out Happy Creek Falls from the trailhead, or take Skagit Tours boat cruises on Diablo Lake for more hydroelectric project history.

This article was created with AI assistance and human editing.

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