You may not have known them because we are referring to Western Yellow Jackets as "meat" or "trash" bees. They are found in the states west of the Rockies.
Now I remember not seeing any in Texas and Nebraska. The first time I had a BBQ in Omaha I was covering my food and looking around in the air all paranoid like. My girlfriend asked me what I was doing and when I told her I was watching for meat bees she had no clue what I was talking about and thought I was crazy.
I don't think your Yellow Jackets are anything like these little bastards. Ours are half the sise of a Honey Bee, eat just about anything a human will, and they love booze, especially beer. I always make sure my drinks are covered as well as my steaks. They are a pain in the a$$ by mid summer when their nests get big.