Highway 191, south of Boseman, Mt

We have traveled 287 through Ennis. Nice rv park in Ennis. You may do better picking up I-15 west of. Butte. 287 isn't bad for 2 lane hwy but faster down I-15 out of Butte. If you are just rambling with no time schedule 287 is fine. Ennis is nice little town. I've gone trough it a lot cutting through Yellowstone from Cody. Personnally I wouldn't go out of my way to go that way. I would stay on I-90 to Butte then south. In fact I would cut across I-80.Watch for wind gusts west of Cheyenne. Go across bottom of WY. Stop at our famous Little America west of Rock Springs..Free over night. Good food. 50 cent ice cream. Then down to Nephi, UT. Free overnight at flying J. Then south to Vegas. AZ Charlies on Boulder hwy in Vegas & on to CA. We live north of Cody. Travel the route often to CA. Lived in CA for 40 years. Fuel up at Flying J in Rock Springs before Little America. JMHO.