From Mark Readdie of Big Creek, exclusive to bigsurkate:

They have to deal with daily unpredictability at the Regent’s Slide. The work is complicated by significant instability of the rocky material they are encountering and the steep slope they’re working on. They are diligently working every day they can (when it’s not socked in with fog and when the slide isn’t falling apart) but all I can say is it’s slow going. Every day they have to check for new cracks above and below the working bench. The material below the bench is falling apart on its own. I watched twice now in the past few weeks where huge rocks just came off by themselves below the work bench. The spider excavators are cabled to bulldozers in case the whole thing goes. 

Here is a video Mark took that he shared with me. This will give everyone some perspective.