The Green Bank Radio Observatory in WV is in a dead zone. It's why the place was built there, it's literally in the middle of nowhere.
It's just east of the Allegheny Front and at the beginning of the Ridge and Valley region of the Eastern Appalachians. Millions of years ago a chunk of what was then then Africa hit the east coast of proto-North America and caused a limestone plate to fold and form the Ridge and Valley Region. It ran over old volcanoes in the region, giving rise to the hot springs in the area. The mountain that looms behind the Observatory is sandstone, like all of the bedrock for 200 plus miles west.
When the place was built, laws were enacted to restrict the power of TV and stations in the region to keep the dead zone dead. There's a network of FM repeaters based in a town to the south to provide news and weather info to the locals. It's an area of heavy snows.
A few miles north of Green Bank there was Naval base built at 4300 feet above sea level and 200 miles from the coast. Strange,eh? It was there to take advantage of the silent zone. It monitored Soviet submarine and spy ship traffic in Atlantic. When 9/11 happened, the listening antenna's were modified and turned inward to monitor cellphone and radio traffic in this country.
The place was sold to a private group a few years back. Who knows what their plans for the place are? It's not far from tourist area's, maybe they'll make it a playland for the kiddies?