This Washington Lake Preserves Sunken Objects for Decades Thanks to Rare Glacial Chemistry

Lake Crescent, Washington

Most lakes don’t turn logs to stone, but Lake Crescent isn’t most lakes. Carved by glaciers in Washington’s Olympic Peninsula, its bizarre chemistry comes from a lack of nitrogen.

Meaning no algae, impossibly clear water, and a depth that might be even greater than the official 624 feet. Plus, it’s home to two fish species you won’t find anywhere else on Earth.

Here are more interesting facts about the strange and amazing Lake Crescent.

The Lake’s Unknown Maximum Depth

No one knows exactly how deep Lake Crescent really is, even though the official depth is listed as 624 feet. The lake bottom has steep cliffs and varying depths that make it hard to map completely.

When scientists tried to measure the entire lake in 2013 with special sonar equipment, they ran into problems. The water was so clear that their tools couldn’t work properly in some areas.

Divers have found trees deep underwater, suggesting there might be even deeper parts that haven’t been discovered yet.

The Lake’s Own Species of Trout

The Beardslee trout lives only in Lake Crescent and nowhere else in the world. These fish started out as regular rainbow trout but got trapped in the lake thousands of years ago. Over time, they changed and became different from their ancestors.

They grew much bigger, reaching up to 20 pounds, and developed a blue-silver color instead of the usual rainbow trout colors. Because these fish are so special, there are strict rules about when and how people can fish for them.

The Unusually Clear Water

You can see about 60 feet down into Lake Crescent’s water, which makes it one of the clearest lakes in Washington. Two main things keep the water so clear: there’s very little nitrogen to feed algae, and the water doesn’t contain the fine rock dust that makes other mountain lakes look cloudy.

The lake’s special clearness comes from how it was formed by glaciers, which left very little fine sediment behind. Scientists have measured visibility up to 82 feet deep on the best days.

How the Lake Was Created

Lake Crescent exists because of a huge landslide that happened about 8,000 years ago. When tons of rock and dirt slid down the mountain, it blocked the Indian Creek valley and created a natural dam.

You can still see evidence of this ancient landslide today. Large boulders sit scattered along the lake’s southern shore, and scientists have found layers of sediment at the bottom of the lake that show exactly when this dramatic event occurred.

The Lake’s Cold Water Temperaturet

Lake Crescent stays surprisingly cold all year round, even during the hottest summer days. The surface water rarely gets warmer than 65 degrees Fahrenheit, while the deep water maintains a chilly 39 degrees throughout the year.

The lake stays cold because it’s very deep, averaging 300 feet, and mountain streams constantly feed it with cold water from melted snow. These cold temperatures help keep the water clean and clear.

The Lake’s Second Unique Fish

Besides the Beardslee trout, Lake Crescent has another special fish called the Crescenti cutthroat trout. These fish evolved from regular coastal cutthroat trout after being isolated in the lake for thousands of years.

They look different from normal cutthroat trout, with a silvery color instead of gold, and they can grow up to 12 pounds. These fish prefer to swim in waters between 50 and 100 feet deep, where they hunt smaller fish and insects.

The Underwater Forest

An old forest stands preserved at the bottom of Lake Crescent, submerged when the landslide created the lake 8,000 years ago. The trees, mostly Douglas fir and Western red cedar, haven’t rotted away because the water is so cold and low in nitrogen.

Scientists study these underwater trees to learn about what the Olympic Peninsula’s forests were like thousands of years ago. The sunken trees also provide homes for the lake’s fish.

The Lake’s History as a Water Highway

Before roads were built around Lake Crescent in 1922, boats were the main way people traveled across the area. Every day, boats carried mail and passengers across the lake to connect different communities.

At least six regular boat routes operated on the lake in the early 1900s. You can still find old docks and boat markers along the shore, especially near Lake Crescent Lodge.

The Lake’s Special Weather Patterns

Lake Crescent creates its own weather patterns because of how it sits between the mountains. In winter, warm air often gets trapped above cool air near the lake’s surface.

The lake’s location between the Olympic Mountains and the ocean creates regular wind patterns. These winds typically blow from east to west in the morning and west to east in the afternoon, which affects both the weather and activities on the lake.

The Lake Bottom’s Historical Record

The mud at the bottom of Lake Crescent tells a 12,000-year story of the Olympic Peninsula’s environment. Each layer of sediment shows evidence of past events, including earthquakes and volcanic eruptions.

Scientists have found proof of six major earthquakes in these layers, including a massive one that struck in 1700. The sediment also contains ancient pollen that shows how the types of trees in the forest have changed over thousands of years.

The Lake’s Effect on Local Wildlife

Lake Crescent influences the environment for three miles in every direction by keeping nearby areas warmer in winter and cooler in summer. The lake provides moisture to the old-growth forests around it, helping huge hemlock and Douglas fir trees thrive.

There are a wide variety of birds that live near the shore, including rare species like marbled murrelets and northern spotted owls. The clear waters support many native fish, creating a rich and healthy ecosystem.