The Large flocks of geese you are hearing are most likely a sub species of Canadian geese, been hearing them every night too. They sound like lessers or cacklers which are a smaller subspecies of the greaters that your probably used to hearing around your local golf course. They have a high pitched squeak sound to them rather than a low guttural honk of a greater. I've also heard some specklebelly geese up there too, which have a high pitched squeak with a quick double note to it