I learned of this place on PBS tv a year or so ago. It is in SD.
http://www.tinkerkennels.com/
I have a bit of a long, involved horse history but we have had no horses since '91.
Yet the one thing I would like to do before I die is to see a tall grass prarie from the back of a horse. The visual perspective from the back of a horse is one greatly appreciated by those of us only 5'0" tall.
So this year or next I am going out there; hopefully to just ride along on a hunt or if it's 'off season' along on a dog training scession.