We take US2 from the Mackinac bridge to I-15 in western Montana each time we go to Alaska (six times so far). We boondock ar local town parks, turnouts, rest areas, and unused weight stations along US2. You will also find Walmarts along the route that can be used. We love the laid back run along 2 and the scenery. If you want something to keep you looking, see how many US Minuteman Missile sites you can spot along that route. Some are right along the highway.
One tip, however, is that you should not try to stay anywhere near Williston, ND due to the huge growth of the oil drilling and support structure in that area. No overnights in the Williston WM, and even getting a rig into that parking lot is problematic due to the heavy traffic.
