Hello, Rosemary! I was born and raised in Central NYS! Ever hear of a tiny village called Homer?

I'm going to make an educated guess, which is all anyone can do with the information at hand. My guess is that you walked across a breeding area for Cicada Killer wasps, a type of solitary ground wasps known for building up pretty substantial communities, even though each chamber is a solitary one.

Another clue for me is that you were bombarded all of a sudden and then left alone all of a sudden. The males of this species are very territorial...up to a limit! They will act feisty as heck for a few feet and then go away. The males can't sting so try to make up for it in bluff. The females are pretty much totally disinterested in defending their nesting chambers and will only sting if personally cornered. I stepped on one several years ago and have to report that it was a memorable event. ;-)

Another clue is that there have been a LOT of questions about this particular insect in the GardenWeb forums of late. This must be an active time for them.

The final clue is that you mentioned their size. Cicada Killers are big. Take a look at the Google images to see if these might be your critters. If not....."never mind".

Here is a link that might be useful: Cicada Killer wasps

very good site