Obviously, when I go to Google this or search virtually anywhere I get a list of state abbreviations.
But I'm curious, what would the proper way be to abbreviate the actual word state?
I would recommend either "ST" or "St", without a period (to avoid confusion with the abbreviation for "street"). I live in Washington (the state, not the city), and "Washington St" wouldn't strike me as odd if I read it in a magazine or newspaper. It doesn't look like there's a very rigidly defined standard on this.
But then, NBC seems to like "Washington St."