SKS777FLYER:
I will SWAG (scientific wild-ass guess) of converting JAC's 6,300' runway length to a sea level equivalent. I would equate it to a 7,300' sea level airport.
wild-ass guess? yeah, sure.
Scientific? Don't think so.
Higher elevation => more runway required;
thus lower elevation => LESS runway required.
So 5300' would be a closer SWAG.