The recent imperative by VoIP service providers to make their E911 service compatible with the U.S.' nearly 8,000 Public Safety Answering Points has generated a new focus on what these PSAPs are and what they do.
One might think that PSAP territories totally overlap jurisdictional city and county boundaries. No, they don't.
So what PSAP are you in? I've just found a link to the FCC Master PSAP Registry List. The list is in Excel format. That's a grab from the list at the top of this post.
Each PSAP listing has details including the PSAP number (often cited on promotional literature by companies such as Vonage), city, county, state, and jurisdictional authority.
Interesting and important reading.
But nowhere near as important as the work they do. Here's one in Vermont: