Blackjack Where IS surveillance?

This is a question I've been pondering for some time. Many years ago (before EITS), I heard that the surveillance people were on catwalks above the ceilings. With all of today's technology, there's no need for them being overhead or even on premises.
The big places surely must have their surveillance people on site but what about smaller places (in the midwest, for example). Are their cameras fed to people in Las Vegas, let's say? A little store in northern MN with only 2 BJ tables surely doesn't have on site surveillance people beyond the "floor", I'd think. Where is the guy they talk to on the phone?
All answers appreciated.

muffdiver

Source.

 

The surveillance office could be placed anywhere. It's typically in the back of the house somewhere, sometimes on a level below the casino. I know at Cal Neva in Reno it's right off the parking garage because at one time you could look through windows and see it. Modern casinos do not have catwalks over the 21 pits anymore.