When we drove up the next day to Mt St Helens, we were shocked.
After we reached a certain point, the landscape was no longer forests, but a barren landscape with blacked ground, burnt and fallen trees and randomly scattered boulders. From Johnstone Observatory we had a perfect view of the mountain. We learned that it had erupted over 20 years ago and was a recently active volcano. It was so exciting and funny because there was snow outside yet it was almost 30 degrees C.
Mt St Helens used to look like Mt Rainier but more like an upside-down cone, until it's north-western side blew off in 1980. The force of the blast was enormous, and with the landslide, mudflow and blast the eruption flattened a huge area of forest, killed 57 people and generally devastated the area. It was incredible to still see the devastation even after 29 years, with a few young trees growing up amongst it all. Now there is a new dome growing in the caldera, which will presumably have its turn at erupting one day.
We spent a night by the lower Columbia River, watching the boats go by, then drove to the Ape Cave, located on the south side of Mt St Helens. The Ape Cave is a lava tube, formed in an ancient eruption of the volcano. The lava tube is rather like a railway tunnel, a long cold dark winding tube made of basalt. It was a bit scary as we walked right to the end, about 1km underground, then turned around and went back again.