I probably would head out Hwy. 80 until Cheyenne where I would head North to go visit Mount Rushmore before going up to Hwy. 90 which I would take into Minnesota, At least that's what I would do. Have a Great Trip!
Walker is in north central Minnesota, almost due east of Fargo. So it makes sense that the shortest route uses various diagonals to get I94 in North Dakota.
US93 to Twin Falls is a frequently recommended alternative to I15 for heading north from Las Vegas. The Google maps recommendation then proceeds north to W Yellowstone and then I94. Both legs are the easiest routes to Yellowstone. The rest of the way is I94.
Considering that the alternative is the climb from SLC to Wyoming on I80, I wouldn't rate the north route as that mountainous. An alternative is to cross form I80 to I90 in the middle of Wyoming, either with US# highways or I29. This basically stays in broad valleys. There's a modest diagonal on I94 from Billings to the state line.
* This post was
edited 04/08/12 01:52pm by paulj *