If you've got plenty of time for it, here are a few suggestions. 
* Starting your morning in Kalispell, have breakfast at Sykes, then walk kitty corner to Black Rifle Coffee and order a Smokey Joe.
* Stop at Machine Guns Montana for an excellent selection of ammo and great prices on NF scopes, Proof barrels, etc.
* Stop in Rollins at M&S meats and get some jerky and cheese curds.
* Didn't buy cheese at M&S? Polson has a small cheese factory with excellent cheese, and if you didn't purchase any at M&S, buy some here. Skipped breakfast? Grab lunch at the Hot Spot Thai place or some BBQ at Cherries.
* Missoula has a few big box stores, Scheels, Bob Ward's, Sportsman's Warehouse, Cabela's, but if you're an archer, stop at Straight Six Archery on Reserve St.
* Continuing south to Hamilton, stop and grab a burger and fries at Naps, but prepare to not be hungry for dinner!
*South of Darby, you'll see a scenic pullout for an epic view of Trapper's Peak. Stop here and enjoy the view. This is the tallest peak in the Bitterroot range. 
* Continuing south past the Connor cutoff, the highway parallels the E. Fork of the Bitterroot River. 
* Keep your eyes peeled as you may have the opportunity to see some big horn sheep by the hwy.
* If you're feeling worn out and need some relaxation, stop at Lost Trail Hotsprings for a quick soak and a true Montana experience. My great grandfather poured the concrete for the pool, and my last name is still stenciled in the concrete. I'm a rare breed in Montana anymore, as I'm a fourth generation Montanan. It's sad to see what my state is turning into, but I digress.
* Once you get to the top of the pass, you can turn left towards Big Hole and visit the Big Hole National Battlefield. The Big Hole is a beautiful area and is true Montana with multi-generation cattle ranches. In high school, we'd drive there and go through a ton of ammo shooting gophers. 
* If you don't turn left, you'll see Lost Trail Ski area on your right and will shortly be leaving Montana and entering Idaho. 
Enjoy your trip!
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