I think you are talking about air cargo carrier, which is based out of MKE, dont know much about them except that they fly, out of the west and east coast ,and the midwest.
they also fly packages for UPS. hope that helps, happy holidays.
When I was carrying cargo out of Dallas Love (DAL) I would see one of SKyways Shorts come in every once in a while. But, I do not think that DAL was a base for them.
One of my stops was at Will Rogers (OKC) and I know they had several of their shorts on the ramp there. So assume that OKC was one of their bases.