There are Canadian Customs facilities at YHM. Up until a year ago, US Airways Express offered daily YHM-PIT service since 1988.

If I'm not mistaken, there are some charter flights to southern destinations during the winter travel season.

I don't think AirTran, etc. would want to serve YHM given the excess government taxes and fees for transborder flying.

Other airlines that have come and gone include CO (YHM-CLE), NW (YHM-DTW), NX <remember them?> (YHM-LGW), Greyhound Air (YHM-YWG), Canadian Partner (YHM-YOW, YHM-YUL), AvAtlantic (YHM-LAS)