Mt. Mazama

Millennia before the establishment of Crater Lake National Park -- and long before the existence of a lake, for that matter -- there was a mountain. And what a mountain it was.

More than 400,000 years ago, Mt. Mazama began its building process with cracks in the Earth’s crust, signaling the rise of a great new stratovolcano in southern Oregon. In time, a vast magma chamber supplied much of the raw material for the building of Mt. Mazama.

Increasingly, violent surges from below piled volumes of molten rock, ash and pumice on the surface, according to noted geologist Howel Williams, a University of California-Berkeley professor who wrote the definitive tome of the region. Eventually, periods of cooling and hardening alternated with episodes of eruption. 

“After more than a million years, Mt. Mazama had risen to a height of almost 12,000 feet, towering far above its neighbors,” Williams wrote. “In the whole length of the Cascade Range, there were few volcanoes that rivaled it in size.”

Myths of epic battles between Llao (Mt. Mazama) and Skell (Mt. Shasta) -- like many great folk tales from other lands -- are based on fact. Nearly 7,000 years ago, Mt. Mazama violently shook the Earth and belched mushroom clouds of smoke. Flaming lava surged at the summit and the parasitic cones on the side of the mountain.

For months, volcanic ash and dust storms enveloped the peak and blackened the sun. The people of the marshes knew the mountain only by sound and the trembling Earth at their feet.

Finally, the pace of events quickened, according to geologists. Then, without warning, Mt. Mazama released a giant, billowing cloud of black smoke -- punctuated with bursts of lightning -- high into the atmosphere. Avalanches of hot ash sped down every mountain valley, incinerating everything in its path. Lethal gas fumes engulfed the native villages in the marshes.

As the cataclysmic activity grew in strength, the winds veered toward the northeast and carried smoke and ash as far away as Montana, Alberta and Saskatchewan. The next time the people of the marsh were able to gaze toward the mountain -- to their surprise and astonishment -- the top half of the mountain had vanished. More than 5,000 feet of mountain summit had virtually disappeared.

Today, geologists concur that the summit of Mt. Mazama collapsed within itself when the pool of magma drained or was expelled as ash, creating a huge cavity inside the mountain. In short, the mountain could no longer support its own weight.