This was a quick side trip I had wanted to do after reading about it Susan Hough's Finding Fault in California. It is near Lake Crowley. I just took the McGee Creek Road off HWY 395 and, after about 5-10 minutes going on a narrow road, came here. In the middle of the following picture you should see what looks like a trail that heads straight up:
What happened was that in June, 1998 there were two earthquakes. They do not know which one produced this, but it was either June 8th or 14th. The boulder, about the size of a small car, came down here and carved into the hillside the faint trail you see in both pictures. It also trashed the road before it reached its final destination in the campground. The road has obviously been repaired.
Check out what they say here under the Hilton Creek Fault Scarp. The magnitude according to this source and the book above was around 5.0-5.3.