Tour of Idaho-Dual Sport Friendly parts?

I've been looking at the information for the "Tour of Idaho" ride: http://www.motorcyclejazz.com/TID.htm . 1300 miles of mosly dirt. From the various writeups I've seen, parts of this (particularly the southern most part) look to be a little too advanced for a rider of limited experience on a dual sport. However, many pictures of the central and northern parts look fine. I'm familiar with some of the more northern parts from ATV rides, but not a lot. So, has anyone here tried this route, and if so, can you recommend parts that are friendly to a coupld fat old guys on DR650s and KLRs?

I'm thinking of riding to Darby, MT, hittint the Magruder Corridor (easy ride, we have done it on quads, could do it in my Pontiac) and running the balance north to the Canada border, or at least to Coeur d'Alene, our home base. I'm particularly interested in how the section from Elk City to the St. Joe Road looks, I have a handle on the rest.

Thanks all.