The marriage of Thos. Peterson and Mahala Boots was likely in Randolph County. The Boots have presence in Delaware and Grant counties as well, but this particular event was likely Randolph, near the Ohio state line east of Indianapolis.
You may or may not know that reading an Ahnentafel is facilitated by its numbering system, that the ancestors of any given number are a multiple of two for the male and by two plus one for the female. Thus: if my number is ten, my parents are 20 and 21. And so on back in time. -Lew Ellingham