Comment: Cracked column basalt and a transition forest that goes from oak savannah to rain forest conifer to rain shadow pine to oak savannah to high desert.   The slides will be released by water freezing and expanding,  and then thawing,  and rain lubricating the now loosened rocks.   Freezing is one of the important factors.  And rain on frozen ground can be a flash flood event.

Dead,  burned trees,  rot at the mean annual winter  snow level,  be that one foot   or four or more.  You can actually accurately guess the mean annual winter snow level by the height of the stumps from  blowdown in a burn area.  The real danger over time will be snag toboggans rocketing towards the railroad and freeway.....or the back of your home.  

Salvage log or not (that area is mostly helicopter logging ground),  the dead trees will fall.  The issue is who gets to control the aftermath.  My life experience includes fire watch duties,  and when the afternoon humidity dropped,  trees fell.  Wet rot dried out.