This fossil was found in Powell County, Kentucky. The rock might some sort of red sandstone and was found where plant imprint fossils are found. According to the Kentucky Geological Survey website, "Only one insect wing has been found in Kentucky, and it was found in the Eastern Kentucky Coal Field. These are extremely rare fossils. Veins within the fossil do not radiate outward from a mid-line or stem as in a leaf." (http://www.uky.edu/KGS/fossils/fossilid.htm). So if this wing imprint it would be a quite rare find.
If you have any analysis of this please leave a comment or e-mail me at louisvillefossils@blogspot.com
This imprint is about 5.5 inches or about 14 cm long.
Imprint with a man's hand to get an idea of the size of the imprint.
The rock has some other impressions as well.