Here is the public Google map created by Rockhopper on another board:

SFMI Google map

Click on SFMI. Zoom in below the town of Murphy. Ridge Road seems to be the same as Silver City road from marker at the turnoff from 78 to about halfway to the Sinker Tunnel turnoff. Left-click on a marker for its description. There is also a marker labeled "proposed SFMI dump site" which is now a parking area. Wonder if this has anything to do with the new mill property?