I will be driving from the East coast to Portland, OR soon, with my last scheduled stop in the Denver area. I have a very small car - 1L, 3cyl. It's a wonderful car overall, but with such little power, I would like to take a route which requires the most gradual continental divide climb, or a climb at a low elevation. This seems to be I80 N to Cheyenne to I84 W. I am also toying with going through Yellowstone as I've never been there, but it seems to lots more up-and-down through there. Any experiences?