Okay, so it's not the biggest landslide you ever saw but it is a landslide. We think a small tremor caused the cliff edge to crumble and fall. Our San Andreas Fault Tour goes where most of the activity occurs along the faultline. The canyon walls are mainly made up of sandstone conglomerate so it does crumble easily. We also had some precipitation out there which can also cause the sandstone to become lose. Enjoy the video!