Montana 89, 12 and 83 vs. I-90 and 93 to Glacier?

I also took US 2 East to Browning and walked through the Plains Indian Museum, then over to Cut Bank for the night at Riverview RV campground. I then went east to Shelby where I Jumped on I-15. 2 is a nice two lane road with little traffic. IMO East Glacier is nicer than west glacier. Be sure to see Two Medicine Lake and Many Glaciers Lake while on the east side. We took I-15 south to Great Falls then stayed on US 89 through the Little Belt mountains and spent the night in White Sulfur Springs at the Conestoga RV Park. 89 is a designated scenic drive and does have some long grades with many scenic view points along the route. Highway 12 east of White Sulfur Springs is under construction and is restricted to one lane traffic.

I just went to Glacier coming from the East. I got off I-94 at Glendive MT and took MT 200 to MT 24 to the Corp of Eng down stream camp ground at Fort Peck Dam where I spent the night. From there I went North a few miles to US 2 then West into the park.
On the return trip I took US 2 East to Browning, US 89 South to Great Falls then stayed on US 89 into the Little Belt mountains and spent a few nights at a FS campground South of Neihart. From there I went South on US 89 to US 12, then South on MT 3 to I-90 at Billings MT.

Your route depends on what you want to see. We have taken all three routes and the road through Seeley Lake is definitely the most scenic. The town really is crowded in summer and parking can be a problem. But, if you like narrow, hilly streets, 19th-century buildings, good restaurants, unique shops, and maybe even a weekend craft fair, it can be a fun small-town stop. And you can always stay in an RV park and use the toad to tour the historic part of town.

Missoula to Flathead Lake and Kalispell is the long way around and not as scenic as Hwy 83. Missoula is a small city (70,000) and Kalispell is a big town (20,000) and both have lots of traffic. You would be able to stop and see Butte if you go all the way to Missoula.

The easiest route, if you are not real comfortable driving on winding mountain roads, is through Helena and north on US 89. Helena is the same size as Missoula, but you will be on I-15 through town if you come north on US 12/287, so in-town traffic isn't really a problem. If you don't need to stop, you can be through Helena in 15 minutes. It is the state capital, however, so it is worth a stop or maybe even an overnight. Unlike Missoula and Kalispell, Helena started as a mining camp, so is more interesting if you like museums, historic buildings, and gold rush/mining history.

Have a great trip!

If you decide to take Rt 83, you can take it to Columbia Falls and US 2. This way you will miss the Polson to Kalispell experience and the downtown Kalispell cluster.

Assuming you are coming from the East, I would either go to Three Forks and take HWY 287 North toward Helena. HWY 12 joins 287 in Townsend. Follow HWY 287 to 89 to Browning. This is mostly 2 lane road and much of it runs along the Rocky Mountain Front out in farm country. Not much traffic on this route once you get North of Wolf Creek. I live in Helena and have driven to Glacier this many times pulling my 35' 5er. You could also go to Missoula and take 93 North. Mostly 4 lane although on HWY 93 there are stretch's of two lane. More traffic on this route but good road. You could also exit I90 at HWY 200 just before Missoula and go over to HWY 83 up through Seeley Lake. This is a beautiful drive but is long strech of two lane that can see heavy traffic in the summer. If you are planning on going to the East side of Glacier, take my first option for sure. If you are going to the West side, you take any of the three.