Watching what's flying over my head here in Anchorage using Plane Finder Pro and it's virtually all 747 freighters on the way back and forth to the Far East. Looks like Fedex and UPS are using it as a cargo sorting facility. I'm told by our pilot in the caravan that it's a lot cheaper to fly in here and refuel as it cost a lot more to fly a fully fueled freighter aircraft the full long distance non-stop.
