Yellowstone and points northwest
baraff, we crossed the northern tier in '12, leaving Cape Cod late Sept and arriving Seattle 2nd week November. Pretty much the I-90 corridor from OH west, except we did not go through Chicago. We had stellar weather, no problems. My research at that time indicated that the probability line for snow through MT, ID, and WA seems to rise most sharply mid-November. Of course, no guarantees in real mountains.
John & Diane, Fulltimers. RVM103 NHSO
On the road since June '12 with Lincoln, the guard cat.
2002 Dutch Star 40, Freightliner, Cat 3126, 2004 Element