Whitefish/Kalispel/Big Mountain...Good places for a dinner date
First of all, you are going to love the area -- I'm very envious...
Some of my favorites include:
Tupelo Grill (downtown Whitefish) - it is described as "continental cooking with southern flair" (you may think, "southern in Montana?", but trust me, it's good - the chef grew up in Louisiana)
McGarry's Roadhouse (Whitefish) - here is where you will find steaks, seafood, pastas, & tasty house fries
Truby's Wood Fired Pizza (downtown Whitefish) - exactly what it sounds like
Buffalo Cafe (downtown Whitefish) - great breakfast spot
Hellroaring Saloon (Big Mountain Village) - if you go skiing (which I'm assuming you will), this is the best lunch spot
Great Northern Bar (downtown Whitefish) - fun place for your apres-ski beer
I just reread your post and realized that you were only looking for a dinner restaurant, so I'd say Tupelo Grill or McGarry's. I left the other recommendations just in case. Have a good time!