[ceejayoz]

You may be interested in https://en.wikipedia.org/wiki/United_States_National_Radio_Q...

Residents in this part of West Virginia can't have cell phones, Wifi, and you can't even drive a car with spark plugs within a mile of the telescope.

[semi-extrinsic]

It looks like all the restrictions on common consumer equipment are only within a 20 mile radius. The restrictions in the major part of the zone are on high power transmitters (i.e. TV and radio broadcasts).