The Cammo Dudes are members of a private security firm, EG&G Technical Services, Inc., guarding the outer perimeter of Area 51. Most of them wear camouflage outfit (hence the name), and they patrol the border in white Jeep Cherokees or in the newer champagne golden Ford F-150 or Chevy 2500 pickup trucks. They can usually be seen sitting on top of a hill near the signs at Groom Lake Road, watching traffic on the road through high-powered binoculars.
After dark they can often be seen patrolling Hwy. 375 between Groom Lake Road and Rachel, sometimes several times a night at all hours of the night. They go in and out of the base on either Groom Lake Road, Mailbox Road or the North Gate (Rachel Back Gate). Sometimes they turn off their headlights and use night vision equipment when driving on the dirt roads.
The Cammos do not have legal authority outside the restricted area, and in fact are under order to avoid all contact with civilians. However, if you cross the border for ANY reason, they will detain you immediately and call the Lincoln County Sheriff to arrest you. Then the mandatory $1000 fine is the least of your problems. Technically they can even shoot trespassers, but this has never been enforced.
Cammos are quite paranoid about being recognized by curious Area 51 tourists [they might be your neighbor... ;-)], and will do all kinds of things to keep you from seeing their face if you manage to get close enough. My favorites are pulling down the sun visor of their Jeep, or casually covering part of their face with their hand. Rumor goes that if a recognizable photo of a Cammo is published, the poor guy will loose his job.
Despite their tough appearance the cammos are only the outer security ring around Area 51. Their authority even inside the restricted area is limited. Inner base security is almost certainly Air Force Military Police, and trespassers unlucky enough to make it past the lines of the cammos are in REAL trouble...
Below are some photos of the older Jeep Cherokees. More recently, most of the Jeeps have been replaced with newer model trucks: Ford F-150 and Chevy 2500 4x4.