First off, I believe you can no longer legally collect animals on the actual Okeetee Hunt Club property, but I may be wrong on this. I also believe most of the corns from the region are actually Jasper County (which is the county the club is in)with the acceptance that corns do "cross the road"-LOL!! There are just too many "Okeetee" corns caught from a larger area than just the hunt club. Several breeders will actually post where in the region the stock is from (ie., Haphazard Road, X town South Carolina, etc.).
As far as locality with CB animals, as long as the founding stock was captured there, then all babies produced are still considered that locality because there was no mixing of genetic material from other areas. It still doesn't mean they will all be screamers. However, remember that breeders generally only line breed the best of the best from the localities and cull out the ugly ones to further enhance the locality/looks issue.
And I would take a screamer "Okeetee Phase" over an ugly locality animal too. However, its nice when both locality and killer looks are combined IMO. Better yet would be to catch my own screamers from the area!!!
KevinM