I read a description of the trail, sounds like it is a good one indeed! The only off-pavement my 1995 Legacy wagon ever saw were gravel roads near Lake Superior.
Have you ever done the Alpine loop? I know it has a difficult optional section on one end, but I am looking at any info about the ground clearance requirements for the main loop. I would also be grateful for any information about the San Juan mountains (for a Subaru). Heck, if I had the time I would pair with somebody and write a guide for Subaru off-pavement, off-road!