There are at least 63 active drone sites around the U.S, federal authorities have been forced to reveal following a landmark Freedom of Information lawsuit.
The unmanned planes — some of which may have been designed to kill terror suspects — are being launched from locations in 20 states.
Most of the active drones are deployed from military installations, enforcement agencies and border patrol teams, according to the Federal Aviation Authority.
Exposed: Location of sites where licences have been granted for the use of drones within the U.S. There are 63 active sites based in 20 states. Red flags show active sites and blue show those locations where licences have expired since 2006
But, astonishingly, 19 universities and colleges are also registered as owners of what are officially known as unmanned aerial vehicles.
It is thought that many of institutions, which include Cornell, the University of Colorado, Georgia Tech, and Eastern Gateway Community College, are developing drone technology.
There are also 21 mainstream manufactures, such as General Atomics, who are registered to use drones domestically.
As well as active locations, the FAA also revealed 16 sites where licences to use spy planes have expired and four where authorisations have been disapproved, such as Otter Tail County, Minnesota.
Unusual: The University of Connecticut — one of 19 educational institutions to own spy planes — is the drone site closest to New York City. The North East is the region with the highest concentration
Concentration: The Beltway around Washington DC has the highest concentration of urban and suburban drone sites, including the U.S. Marine Corp base as Quantico Station, Virginia
The authority revealed the information after a Freedom of Information Act lawsuit by Electronic Frontier Foundation.
Its website hosts an interactive map that allows the user to zoom in to the area around where they live to see if any sites are nearby.
However, the FAA is yet to reveal what kinds of drones might be based at any of these locations.
The agency says it will release this data later.
Most of the drones are likely to be small craft, such as the Draganflyer X8, which can carry a payload of only 2.2lb.
Police, border patrols and environmental agencies, such as the National Oceanic and Atmospheric Administration (NOAA), could use for them effectively.
While few would object to vast open areas being monitored for wildfires, there are fears of privacy violations if drones are used to spy over cities.
Florida: Mostly police and Sheriff departments are registered to use drones in the state
Watch out Canada! Border agents are registered to use drone in North Dakota, just a few hundred miles from Winnipeg, Manitoba