NEW Rv-er with Mirada Class A 29ft Calif. to Spokane

I15 to I90 is not much different in distance from the alternatives. There are several passes, but nothing more difficult that those along I5. On the I15 ID/Mt state line there is a broad upland. I90 on the stateline the pass is a little more defined. That is another modest past in ID. Being further north there's more chance of snow, but those states know how to handle it.

From I15 I think it's a toss up between going north to I90, and going NW on I84 to US395 and on.