Granted I have only moderate experience driving 4WD roads, but I found this one a real challenge for my Xterra (it was my toughest 4WD road to date). I decided to park at about 12,000‘ (mostly because I wanted my hike to have at least 2,000‘ of gain). That point was past almost all of the difficulty- there was one more short (50‘) stretch before very good road until 13,200, and moderate road from there to 13,700‘.
The road was quite rocky and took me about an hour to do the four miles. There were two significant stream crossings that could be (temporarily) impassible during or right after a heavy rainstorm.