how do you find out what hospitals were closed down in the 60's through the 80's?

Answer 1

polk city directory 1960-1990 find them in the local library

Answer 2

If you can get access to the public library, a lot of times they have either old community guides that would list the hospitals available then and you could cross-reference to what there is now. A lot of newspapers did sections that touted "Our Home Town" and had pictures and hype about the medical care, so check with a newspaper office. And you can write to the local Chamber of Commerce and ask. Other than that, not much you can do but ask someone who lived there for a long time.