Thanks, George. There's also a site in the El Pasos which was used by native Americans for tools/arrowheads. I don't recall the name of the rock - it's not obsidian - but looks somewhat like an opaque quartz.
On the topic of avalanches - there were a series of huge slab avalanches on Shasta during the mid-90's (95? 97?). As I recall, one took out the towers of the ski area, and possibly the lodge? The ski area was then moved to its present location. There were some excellent photographs of the one damaging the ski area online at the USFS site, but am not sure they still archive them. As I recall, it was a massive (maybe 20' tall?) wall of slow-moving snow that removed everything in its path.
