An easy route would be go north 14A to the Badger Basin road (294). Left turn on 294 and go westward to 120. Right turn and take 120 until it ends at the "T". Left and enter Bridger. Best fuel stop is Maverik station just north of town. Go north until ends in another "T". Right turn to Laurel. Pick up I90 and then east. Watch your speeds through little towns. Their only source of income is tickets.
On that route you will miss most of steep hills. Across the badger basin look out for antelope on road. North you will go through mostly farm country. East of Billings check out little big horn I90 pretty much an easy drive. We drive that route every week or so to Billings.
