A lake fed by nothing
About seven and a half thousand years ago, a volcano called Mount Mazama erupted so comprehensively that it emptied its own magma chamber and collapsed into the space. What was left was a caldera roughly five miles across, and over the centuries it filled with water.
What makes the result unusual is what doesn't reach it. No river flows in. No river flows out. Everything in the lake arrived as snow or rain falling directly onto it, and leaves only by evaporation or by seeping away underground. Nothing washes in from a watershed, because there effectively isn't one.
That is why it looks the way it does. With almost no sediment and almost no nutrients, there is very little suspended in the water to scatter light, so the blue you see is close to what water actually does to sunlight when nothing is in the way. It is also the deepest lake in the United States, at 1,943 feet.
The only way down
The rim stands hundreds of feet above the surface all the way round, and almost all of it is cliff. There is precisely one legal route from the rim to the shore: the Cleetwood Cove trail, a little over a mile of switchbacks cut into the slope, dropping about seven hundred feet.
It is the only way to reach the boats, and the boats are the only way out onto the water. So everyone going on the lake goes down the same path, and everyone coming off it comes back up the same path. There is no road, no shuttle and no alternative.
Going down is easy enough. That is rather the problem.
The storm
We were out on the water when the weather turned. It came over quickly — the light went, the surface roughened, and what had been a calm morning on a very blue lake stopped being that.
The trip was cut short and the boat went back to the dock. Which meant we were standing at the bottom of the caldera, at the foot of the only trail, with a storm coming through and no way out except up.
Seven hundred feet of switchbacks, in loose volcanic pumice, in blowing dust. Everything on that slope is pulverised rock from the eruption, and once the wind gets into it the air fills. You climb it slowly with your eyes half shut, and there is no version of the day where you skip it.
We got up. The kids managed it better than I expected. It is, in retrospect, the most memorable thing about the trip — not the blue water everyone photographs, but the climb out of it in weather that arrived without asking.
The Watchman, after dark
The other half of the trip was the same lake in the opposite mood.
The Watchman is a short climb off the western rim — under a mile, a few hundred feet of gain, with a stone fire lookout from the 1930s on top of it. Standing on the west side matters: you are looking east across the water, which is the direction the moon comes up from.
We went up in the evening for exactly that. The moon rose over the far rim and put a line of light straight down the lake towards us — a caldera five miles across, with one bright road laid across the middle of it.
Coming back down in the dark, two eyes caught the light and held there in the trees beside the trail. A deer, almost certainly. One of the kids announced with great confidence that it was about to charge us. It did not.
What makes eyes do that is the tapetum lucidum, a reflective layer sitting behind the retina that bounces light back through it for a second pass. It roughly doubles what the animal can do with very little light, and the glow you see is the part that missed on the way out. Deer have it. We don't, which is why we needed the torch.
The rim road
The road that runs right round the caldera is the other way to see the place, and it is worth the full circuit rather than one viewpoint.
Partway round is Vidae Falls, spring-fed, dropping off the cliff face beside the road in a long thin cascade. It arrives from groundwater rather than from any stream on the surface — the same story as the lake itself, water appearing where the rock lets it out.