Parked at Mt. Si TH.  Road CCC Road & CCC Extension, then back to car via MF Rd.  A nice loop even though it was raining for most of the day.  Trails were in good shape.  Lots of overgrowth and downed trees on the northern section of the CCC Road.  A few trees down along the CCC Ext.  Saw 2 other riders.  

If I were to do this again, I would do the same clockwise loop but park at Mailbox TH.  That would get you a bit of a warmup ride before you get to the climb at the end of Mt. Si Rd.