Meet the Oldest Lake in North America

June 22, 2015

From northern Alaska down to the south of Mexico, one lake stands out as the oldest and most geologically unique in all of North America. In Lake County, California, just north of Sonoma and Napa counties, is Clear Lake with a ripe, young age of 480,000—yes, nearly half a million years old—the oldest lake on the continent.

Clear Lake and Mount Konocti

The average lifespan of a lake is usually about 10,000 years. What commonly happens is the depression of the lake fills with sediment, water levels go down and wonderful wetlands are created. While Clear Lake is only estimated at about a half a million years old, geologists figure that lakes have existed on this particular patch of land for nearly 2.5 million years.

How has Clear Lake remained intact longer than any other lake in the US, Mexico or Canada? A geological fluke. There is molten rock deep beneath the lake from long-dormant volcanoes—volcanoes also responsible for the stunning mountains that surround the lake. The molten rock tilts a little bit every year, allowing sediment to seep into the gaps, causing the water level to remain relatively unaffected for a very, very long time.

A half of million years of sediment has deposited enormous amounts of nutrients into the lake, which encourages the abundant growth of plant life. This in turn creates a rich environment for fish and wildlife. In fact, almost half of all species of birds find their way to Clear Lake at one point or another throughout the year.

This fertile environment sustains more fish per acre than any other lake in America. In fact, Clear Lake is known as the best bass fishing lake in the west, and was recently named the No. 2 Bass Fishing Lake in 2014 by Bassmaster magazine, the premiere bass fishing publication in the US. But Clear Lake is not only home to the “monster bass,” it’s also home to the monster catfish. And carp, crappie and blue gills can also be found, and fished for in the lake.

The volcanic activity still manifests itself in the form of frequent “geysers,” which are not really geysers. They’re really fumaroles and boiling hot springs, and they’re responsible for the vibrant system of spa resorts and hot springs from Lake County’s colorful resort past, which included numerous “pleasure palaces.” Today, Harbin Hot Spring near Middletown maintains a successful spa resort, even utilizing natural warm spring waters from the ground in their soaking pools.

Clear Lake is not named Clear Lake by accident. But it wasn’t given its name because of the water, either. Clear Lake was named by settlers in the late 1800s because of the astonishingly clean air found in the region. And the air remains clean to this day, with the California Air Resources Board certifying Lake County as having the cleanest air in California for the last 23 years.

Interestingly, Clear Lake does not get any of the fog associated with Northern California locales like San Francisco. Thanks to the mountains and the midpoint location between coastal California and Central California, Clear Lake enjoys an average of 265 days of clear skies a year.

Combine lots of warm sunshine with volcanic activity and shallow waters and you get a comfortable and warm lake for sport and recreation. The water temperature of Clear Lake averages 76 degrees in the summer, so water sports can be comfortable without the accompanying brain freeze.

It’s no secret that plenty of California’s lakes and reservoirs have suffered in this historic drought. Although Clear Lake is also seeing lower water levels, there’s still plenty of warm water waiting to be enjoyed, whether it’s fishing, jet skiing, bird-watching, kayaking or stand-up paddle boarding. Check out this North American treasure, and see for yourself what 450,000 years looks like.

Photo credit: Nathan DeHart Photography