Winter Rim rises over the town of Summer Lake, Oregon. The actual lake, Summer Lake, is behind us in this view, taken from a city park/wayside that's almost as large as the town itself. I've never been able to tell exactly what's going on in that outcrop up on the rim. I think the lighter layers are tuffaceous sediments, and the darker material lava flows, but from this distance- and I've never been closer than this spot- I'd rather not speculate any further than that.
Followup: Commenter Lyle left a link to a field trip abstract, that like so much in geology, sounds dry and technical. But if you understand it, crazy scary and amazing. Quake-induced landslides, with volumes in the range of cubic kilometers and run-outs in the range of kilometers. My response was that "Summer Lake just got a whole lot more dangerous-looking!"