>>3088493Here's the landslide source.
If you'll notice, the two peaks are in layers, those layers are the Columbia River Basalts that I've been mentioning. Over time, changes in the weathering patterns, including an increase in dissolution and frost wedging as the location drifted to a more wet climate, the integrity of the very steep slopes on this particular part of the Basalts slowly declined, culminating in the collapse and *fucking massive* landslide. Notice how the exposed Basalt layers are followed by steep finer-grained areas with less vegetation? That's the remnants of the landslide, which occurred about 600 years ago. The landslide reached to where I was standing when I took this photo and well beyond, but has since been carved through by the Columbia.
