What is the abbreviation for "state"?

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."

In the US, the word state is generally not abbreviated. When used as parts of acronyms, it is simply referenced as S

NYS (New York State)
LSU (Louisiana State University)
SUNY (State University of New York)

Use of ST or St with or without periods is likely to result in confusion with street.