No Country for Old Men—I mean, obviously. Not even gonna bother posting pics for that one.
Tremors—if you haven't seen it yet, seriously, go watch it. It's a must.

Joy Ride—kind of a horror vibe, similar to The Hitcher.

Vacancy—another horror flick. Setting is basically just some motel off a random American highway.
Fargo—both the movie and the series. If you haven't checked out the show, the first season is definitely worth it, and the third season currently airing is good too... though I wasn't really feeling the second season much.

The Texas Chain Saw Massacre 1 and 2—these are set deep in the middle of nowhere, rural America. Honestly, the second Chainsaw is way more fun than the first part, which you could probably skip if you wanted. To me, the first one feels a little slow nowadays, but it’s definitely set in the American heartland and has a few cult moments, like that scene at the end where the guy is dancing with the chainsaw on the road.

The Hills Have Eyes—back to that whole rural American setting again.

Wrong Turn—might actually be the best horror movie set in the woods. It's got that specific American backwoods atmosphere, so figured I'd mention it.

Rock West—some neo-noir stuff, kind of like Blood Simple or No Country for Old Men, if I remember right.

Looper—sci-fi, but like 90% of it takes place on this "futuristic" farm somewhere in the Midwest.

There's a ton of other movies like this, these are just the ones I can think of off the top of my head. Oh, and I should mention Ice Harvest. Might not be exactly the genre people are looking for here, but it definitely has that "Fargo" feel to it.