The resorts [1] along the north shore of Hebgen Lake offer what there is to be found in the way of food and drink.
The USS Happy Hour Bar (15400 Hebgen Lake Rd., 406/646-7281) is a particularly appealing bar with a view of Hebgen Lake [2]. If it’s choice you want, head down the road to West Yellowstone, where restaurants proliferate.
Links:
[1] http://www.moon.com/destinations/montana/the-missouri-headwaters-and-south-central-montana/three-forks-and-the-madison-river-valley/q/accommodations
[2] http://www.moon.com/destinations/montana/the-missouri-headwaters-and-south-central-montana/three-forks-and-the-madison-river-valley/quake-lake-and-h