What do people stock up on food wise?

Okay, I'm a bachelor and have been cooking the same meals for myself since 5 years ago. But the food only lasts a week. I recently visited Montana up in Bozeman, and this local says right before Winter, people in that area buy food for 6 months (because the roads aren't plowed, they just close them down). What do they buy that lasts them 6 months?