Look for things like this at the perimeter of a site. This is a Windstream install at a site in Bullitt county where I live. I have found three sites around me with newly ran fiber.
I'm pretty sure one of the in progress sites in Louisville has had fiber ran to it, and I think two others do as well, but can't confirm. Looking at Windstreams fiber map, I think they will get a lot of the Louisville area backhaul. They have a lot of fiber through E-Town and Glasgow as well. Not much in BG though. Not sure who else could be backhaul providers in West KY, there will likely be 3 or 4 at least. Sites in Louisville have been harder to observe. Most are either surounded by solid wooden fences, or on private or inaccessible property. Another thing is that a lot of Sprints sites in Louisville are co-located with other carriers, making it harder to tell a new fiber install unless I see it going in.
Windstream Map
http://www.windstreambusiness.com/support/coverage-area
Very interesting to compare this map with the sponsor map.