LAKE TRUCKEE (California)

In Neocene times, which occurred during the late Tertiary Period approximately 25 million to 13 million years ago and encompassed both the Pliocene and Miocene Epochs, Lake Truckee was formed from a basalt flow that dammed the upper Truckee River canyon just below the present-day site of Hirshdale, California. The lake covered an area of some 73 square miles, its surface level reached an elevation of at least 6,000 feet above mean sea level (MSL), and attained a maximum depth of 465 feet. Lake Truckee remained through part of the glacial (Pleistocene) period until the river eventually wore down the obstruction and subsequently drained the lake