At what point is an Eastern considered an Osceola?

[Tomfoolery]

Not sure about osceolas because I've never hunted them. But i think Merriam, Rios, and Easterns could be identified more by their gobble than colors. All 3 have distinctly different gobbles.

[RutnNStrutn]

I've killed gobblers with Osceola-ish traits as far north as SC. I've killed plenty of "Osceolas" in central Florida that looked just like an Eastern. So I'd say the SR70 and south line seems about right.
I've also hunted out in Idaho and Nebraska and seen gobblers that look like Merriams (white) while others look like Rios (buff color).
Here's a bird that I killed in central FLA. He has the black wing traits of an Osceola. Who knows for sure?