Weather for me is a huge factor. You are heading in to winter, US summer. Look at some of the temps. I couldn't live in those places. But some people don't mind and stay in the air conditioning alot or come out after dark. Some people can't stand the cold where I live, but I am out all year.
Middle of country has short winter of sorts. But hot. Out west it depends on elevation.
I have moved, a state or two, but new where, so was easier to start searching homes on line, but still hard cause you don't know which side of town is good or bad.
To me sounds like you want to be in a rural area, for farming. Horses don't need as much land. So prices of land, and how far you can be from a big city. I like small towns, smaller the better. But I realize I like to get a variety of stuff sometimes, which you don't always see in small towns. But the internet is helping with small stuff.
Maybe try working with some group, or maybe even farming forums. If you can find an existing farm for sale, it might be the way to go. Same with horse and stables, though those can be built.
I wouldn't say we have a horse culture in Upper Michigan and Wisconsin, but people have them all over, and there are a few trails for them, but not overly common.
Myself, I would look at climate first and land you can afford. Get on some horse forums or connections in real world, maybe someone place has the perfect stable for sale. I am not sure if you can turn a corn field into a blueberry field. If so, options open alot.
Though farm land I believe becomes expensive when it leaves the family. I think they have some tax deductions, but some lose it at death. Much of it gets sold and subdivided into homes for $$$. So finding a place with enough land to farm, in your soil and climate, and cost, may drive this all.
