Dream Season

Hired by Crater Lake Lodge, Inc. as a tour guide and boat operator for the 1973 season, the opportunity would turn out to be a watershed experience for me, both literally and figuratively.

For one thing, I would have a seminal adventure in one of the most beautiful spots imaginable on the planet. For another, I would live somewhere other than my hometown of Portland for the first time in my life. From a literal standpoint, the position would involve spending every day that summer on a lake so deep, so pure and so blue that -- upon first glance -- it will take your breath away.

The position featured two key requirements: first, the successful completion of the U.S. Coast Guard test for a launch operators license; second, learn everything I could about the history, geology, flora, fauna, birds, fish and insects of Crater Lake National Park. I mean, as a tour guide, I wouldn't feel I was worth my salt if I wasn’t a complete expert on all things relating to Crater Lake.

Diving feet first into both endeavors, I easily passed the license examination to qualify as a launch operator. The second -- to become well versed on Crater Lake and environs -- was a more open-ended assignment but one I thoroughly enjoyed, immersing myself into absorbing everything I could learn about the park.

As it actually happened, however, I spent most of my time answering two basic questions on boat tours around the ancient caldera: “Why is the lake so blue?” and “Are there fish in the lake?”

The water is so blue because it’s so pure. Water molecules with no sediments, algae, pesticides or pollution will absorb all the colors of the light spectrum except the blues. Other wavelengths in the spectrum bounce back, while the blue wavelength is absorbed in the water, creating the indigo blue hue. The key is to have relatively pure water and lots of it (an estimated 4.6 trillion gallons).

As for fish, early visitors stocked as many as six species but only two survived the rigors of Crater Lake: rainbow trout and kokanee salmon. Fishing is not only allowed, it’s encouraged. No license is required and there is no limit. However, access is limited to the summer months (along the shoreline at near the boat dock at Cleetwood Cove and on Wizard Island) and only artificial bait is allowed.

Truth be told, working as a tour guide and boat operator at Crater Lake -- and hence, someone with access to the best fishing holes -- was the perfect job for an aspiring angler. That’s no fish tale.

Fire And Ice

Once Mt. Mazama had collapsed within itself in a terminal cataclysm, the resulting caldera no doubt resembled the visage of hell from “Dante’s Inferno” -- a seething bottom of molten debris, fragments of sharp rock and pools of bubbling mud.

During the growth of Mt. Mazama, episodes of glacier accumulation had alternated with periods of volcanic eruption. Lava flows and showers dissipated the glaciers on the slopes of the caldera, creating torrents of melted water sweeping into the newly formed basin.

So as you might expect, Crater Lake was no overnight sensation. Over the course time, a lake eventually appeared in the caldera: first as series of small pools, then larger pools with connecting channels, and finally as a singular continuous and ever deepening body of water.

“As passing clouds unburdened themselves of their moisture, the level of the lake gradually rose,” wrote Howel Williams in "Crater Lake: The Story of Its Origin." “Four-fifths of the water fell directly into the lake as rain and snow: the remainder was supplied by small torrents cascading into the basin from the encircling cliffs.”

Today, the level lake is fairly constant, aside from minor seasonal fluctuations. Crater Lake has no inlets or outlets. The amount of water added by rain, snow and streams inside the caldera wall keeps pace with that lost by evaporation and percolation through the walls.

As the deepest body of fresh water in the U.S. and seventh deepest in the world, Crater Lake is approximately 1,932 feet deep. Indeed, the lake is so deep that it rarely freezes over, with recorded freezes occurring only in 1924, 1949 and 1983.

The immense depth of Crater Lake acts as a heat reservoir that absorbs and traps sunlight, maintaining the water temperature at an average of 55 degrees Fahrenheit on the surface and 38 degrees at the bottom. The surface temperature fluctuates a bit, but the bottom temperature remains quite constant.

All told, it likely took thousands of years for the caldera to transform from a hellish vision of Dante’s underworld to the heavenly views of the stunningly beautiful blue pool we see today (below, with my Mom posing on one of our trips to Crater Lake).

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.