My first day back in Oregon after almost a year gone, and I am psyched! I went up to Crater Lake and hiked out into the snow for a sunset that never quite materialized. But it was magnificent as always, staring down and out at one of the most beautiful lakes in the world.
For those who don’t know, this is a caldera: a giant hole in a volcano. Calderas usually fill with lakes, at least until they are breached by erosion and drained. This particular caldera was formed when Mount Mazama exploded in a furious eruption about 6700 years ago. It’s estimated that the mountain was a bit bigger than Mount Shasta, making it one of the (former) giants of the Cascade Range.
The large magma chamber underneath the mountain emptied rapidly and gravity took over. The entire peak area collapsed down, creating a caldera. Some of the last volcanic activity at Mazama, some 800 years ago, formed Wizard Island at one end of the lake. You can visit the island on boat tours. I highly recommend you do this if it’s summertime and the tours are running. You can hike to the 763-foot summit and then return to the cold blue lake waters for a very refreshing swim!
By the way, hiking to the top of Wizard Island gives you the all-time best lesson in the difference between a crater and a caldera. Wizard is a cinder cone, a pile of loose pumice and other debris ejected into the air as hot frothy lava and ash. At it’s summit is a crater, the hole left when that debris blasted out of the summit vent. So instead of collapse into a large void beneath the mountain, craters are created by explosion outward. Craters are normally quite a bit smaller than calderas.
Mazama’s position and height make it a magnet for snow storms, so it wasn’t long before the steaming caldera filled with some of the world’s cleanest water. Springs in the porous volcanic debris also helped fill the lake, where evaporation and input from these two sources are now in equilibrium. Visibility down into the lake is awesome, 100 feet plus. In recent times that clarity has fluctuated, and scientists monitor things closely.
Often overlooked when people come to Crater Lake are the beautiful forests surrounding the mountain. On the wetter west side rises the Rogue River, which the writer Zane Gray made famous when he lived and fished its lower reaches. Wandering around the rugged and heavily forested upper Rogue you’ll find big evergreens and crystal clear streams, punctuated by the occasional waterfall.
Enjoy Crater Lake, Oregon’s only National Park!