Lake Tahoe is the oldest lake in North America and the third oldest in the world, according to new research presented at the Geological Society of America’s annual meeting on Monday in Anaheim. The finding places Tahoe in the pantheon of the world’s most ancient lakes. Lake Tahoe is at least 2.3 million years old, according to Winnie Kortemeier, a professor of geosciences at Western Nevada College in Carson City, Nevada. She initially made that discovery in 2012, when she sent samples of volcanic rock she collected near Tahoe City to the U.S. Geological Survey geochronology laboratory for radiometric dating.