I would not recommend any tire width less than 1.5". This is a snowmobile/ATV route with very little other use. I live in the area and use the local road system rather that the trail for riding. Even on a Mt Bike it is diffucult to hold a line due to the large rock size used for the trail surface.

Beautiful country, and a good local road system with not to much traffic make the use of the trail by bikes not worth the grief.