The military has lots of places to test drones that do not involve populated areas. They also do not want people looking at their experimental operations.
If you have read the story about the guy arrested for the Vandenburg drone incident, it mentions that it was detected by a drone detection system and afterwards he had it in his pocket, small yet detected.
Also, flying distances requires autonomous control or decent comms (cell, satcom). In a rural area, pulling cell data from a local tower would likely be in the realm of possibility for the various providers (they keep track of data for billing). Satcom direct to cell is out there too, Starlink has been used to control drones in Ukraine war.
If you have read the story about the guy arrested for the Vandenburg drone incident, it mentions that it was detected by a drone detection system and afterwards he had it in his pocket, small yet detected.
Also, flying distances requires autonomous control or decent comms (cell, satcom). In a rural area, pulling cell data from a local tower would likely be in the realm of possibility for the various providers (they keep track of data for billing). Satcom direct to cell is out there too, Starlink has been used to control drones in Ukraine war.