I rode part of the CCC road/trail and extension. I parked on the Middle Fork Snoqualmie Road and the Bessemer Road gate. With lots of new pavement - driving this was a breeze - only one dirt section of a few hundred yards of bomb crater potholes to negotiate.
Up Bessemer Rd 1 mile to the CCC junction - go right for .3 miles and find the easy to miss trail on the right(sign there currently-if you start serious climbing you've gone too far). Trail for 3 or so miles and you pop out on the MF road(small unpaved section at the moment). CCC Extension Trail starts steeply climbing on the left in about 50 yards(not signed at the moment). Extension trail to the campground and turned around and retraced my steps. (about 15 miles RT)
Lots of small bridges on the CCC Ext. - they are all VERY slippery.
A few easy over downed trees and was able to keep my feet dry on all the creek crossings.