Crater Lake was created when the massive Mount Mazama erupted and collapsed into itself some 7,000 years ago. This catastrophic event devastated the surrounding landscape for hundreds of square miles. Ash from Mt. Mazama can be found as far away as Canada! Roadcuts along State Routes 230 and 138, which bring visitors to Crater Lake, hint at the amount of white ash that sifted down from the long ago eruption. It is said in some places the ash is 400 feet deep!