I don't know if there is a place in Cincinnati but I would think that surely there would be in a city of that size. They must have a Bass Pro and/or a Cabela's. If you check either of these stores, be sure to talk only to the manager of the gun department because often the sales people do not know where the black powder is kept or even if they have it. However, as Trent said, Friendship is not that far from you and the magazine is open during the Spring and Fall shoots. They have the best prices anywhere (for members only) and they have almost any brand or granulation you might want. If you are not as member of NMLRA, you need to join. Then there is Deer Creek in Waldron, Indiana as Many Kaltch mentioned. I have bought a lot of powder from them and their prices have always been very reasonable.