For years I've been writing "Washington State" (all capitalized) when necessary to distinguish from "the other Washington", and while I am a linguistic relativist, I defer to consensus when I see it. I am shook to learn that the Chicago Manual of Style's latest edition now joins the AP Stylebook in recommending "Washington state" (no capitalization) instead.
"State" still applies when talking about the university (#WSU), or of course when using CamelCase for hashtags like #WashingtonState




