Go to http://en.wikipedia.org/wiki/Flora_of_Ohio
look at the list for Vitis near the bottom. Any link that starts with vistis is a wild grape identified as being flora in Ohio. Compare the description and the leaves, vines etc. from the pictures with what you have. If you don't find your grape, and since you are in SW Ohio change the last word of your link to a neighboring state and search those links also.