Wed Jun 10, 2020 6:19 am
Based on your description, it seems to me that the sirens in those areas probably belong to individual fire departments and are not part of a siren system. With different technologies and wireless reception in different areas, it's those departments' own discretion whether or not they want to/should keep sirens going for their signaling. If those counties you mention are rural and don't have a centralized system of disaster/weather sirens, then some towns will simply not have sirens.
That's how it is here in my part of West Virginia. We don't have any systems here, each fire department just may or may not have their own siren. One department about 10 miles from me got rid of theirs (a Sterling/Darley 3V8) when renovating in 2017 and decided not to get another one because their pagers are reliable enough there. Yeah, it does mean that the resort nearby won't have siren warnings when emergencies are imminent, but... oh well.
Then again, not all sirens are actually located on the main fire department building. In my town, the siren is mounted on the elevator shaft of the tallest building in town. Sometimes it's kept at an older building after the department has moved into a new one. Sometimes it's on a town hall or courthouse. Or a post office or bank or school. I've found sirens in interesting places by spending a little time looking around and it certainly doesn't hurt to try.