What I think a lot of people fail to realize when it comes to farming is that there would be no large scale crop farming to worry about or guard. The reason being, diesel quantities won't last long enough to sustain even small scale farming when using diesel/gas powered equipment. If it's bad enough that this country shuts down, it will do just that. Shut down. No semis hauling tankers of gas/diesel to your nearby station.
If you think you're prepared to plant and harvest even 20 acres(which I think is a decent amount of property that could feed a small group of people year to year) of crops without powered equipment, you might as well shoot yourself now. Not to mention, finding 20 acres of half decent fertile land in anything outside of river bottom territory is going to be a PITA. You can't just run up into the mountains to the nearest box canyon and drop trou on good ground, it doesn't work that way. I pray like hell that if S were to HTF everyone runs to the MO and AR parts of the Ozarks mountains, because that leaves the better areas open to people with a growing brain. That opening scene in Josey Wales where he was plowing isn't nearly accurate as to how many rocks are in the ground up there. They probably hauled in dirt just for it.
Like KillShot said as well, you're going to need water. Anyone with half a brain will know this when SHTF, and will regulate any decent sized spring fed sources. What's that mean to me? I'm not going to count on Roaring River for a water supply without boiling the hell out of it or filtering it. Personally I think filtering it is adding something else you have to carry. If you already have the ability to make fire and a bowl out of something, just boil it.
Bullets as a commodity? I don't see it. Plenty of preachers and snake worshipers survived in the great westward expansion somehow without them. They did so on the small amount of pity in someone else's heart. Just because you have bullets and a gun doesn't mean you're going to run out in a day or kill off everyone else you meet. I'd rather have a few hundred rounds and the ability to evade being found than 10k rounds and my own mountain top.
Lest we forget something I've stated since I learned about the world and some of the history in the last few hundred years. If S ever H'sTF in this country, I think you'll find that all of our allies suddenly remember that they were our enemies at one time, and that they've got something to gain once again.
Just some ramblings from a young hillbilly who's listened to some of his elders that lived through the Depression and otherwise. Take them as you like, they're just my opinions.