[link|http://www.theregister.co.uk/2004/05/25/area_51_hackers/|http://www.theregist.../area_51_hackers/]

Even without aliens, the facility has its secrets, and last year while roaming the desert outside the Groom Lake base Clark stumbled upon one of them: an electronic device packed in a rugged case and buried in the dirt. Marked "US Government Property," the device turned out to be a wireless transmitter, connected by an underground cable to a sensor buried nearby next to one of the unpaved roads that vein the public land surrounding the base. Together, the units act as a surveillance system, warning someone - somewhere - whenever a vehicle drives down that stretch of road.

Similar devices had been spotted in the area in the early 90s, but they were crude and bulky, stashed in the bushes and easily spotted. They were later withdrawn. The new road sensors are more clandestine, given away only by a slender antenna poking up through the dirt. "They're very, very hard to find, because there's just this little wire, like a blade of grass," says Arnu.