It may be out in the middle of the open desert, but someone is always watching.

On the outskirts of the tiny town of Rachel, Nev., about 140 miles north of Las Vegas, lies one of the entrances to the enigmatic Area 51, an outcropping of barbed wire and gate with multiple security cameras trained on whoever approaches on the public roadway.

"It's a surreal experience," Jasmeena Samrai told Fox News. She was with a group on a tour during a trip to the Vegas area as part of a bachelorette party.

'STORM AREA 51': STRANGE TIMES OUT ON THE 'EXTRATERRESTRIAL HIGHWAY

The U.S. Air Force has issued stern warnings for people not to approach the gates of the Nevada Test and Training Range, where Area 51 is located.

Area 51 tested aircraft ranging from the U-2 in the 1950s to the B-2 stealth bomber in the 1980s. The government spent decades refusing to acknowledge the site even existed, before releasing documents confirming it in 2013.

The continued secrecy over the site has fueled rumors of government studies of extraterrestrials and crashed UFOs.

In that spirit, and with tongue planted in cheek, the "Storm Area 51" Facebook event went viral in July as people pledged to overrun the secret military base in an attempt to "see them aliens."

More than 2 million Facebook users have now said they are going, with 1.4 million replying that they were at least interested.

Those set on heading toward the gates without a professional and certified tour group is sure to encounter multiple challenges.

The roads that lead to the gate areas of Area 51 intersect other dirt and gravel roads, making it easy to accidentally end up on private property. Those trekking to the area with the aid of basic GPS -- sans pro guide -- risk hefty fines and jail time, among the many perils.

"If you don't know the areas, you aren't going to know the spots," Ken Sig, a tour guide at Las Vegas Adventure Tours, told Fox News on Wednesday during a lengthy 10-hour tour of the area. Sig described the roads as a "spider web" that make it easy to get lost.

Traveling through the area, home to Joshua trees and scattered wildlife, distant swirls of dust can occasionally be seen that, on closer examination, can be seen as the stirred-up trail of a passing vehicle. On the road to what's known as Area 51's "back gate," a white unmarked truck appeared on a side road before turning off in another direction as other vehicles lurked on more distant hills.

At one point when driving to the gate, a herd of antelope slowly meandered across the road as tour vehicles paused.

'STORM AREA 51' HAS NEVADA DESERT TOWNS ON EDGE AS THEY BRACE THEMSELVES FOR FLOOD OF VISITORS

On the final approach to the gated area, a visitor spied signs warning against leaving the public road and cautioning against getting closer.

"If you are considering trespassing on the Nevada Test and Training Range Boundary, please considering the following consequences," one sign reads.

The possible consequences? How about these?

1. A $1,000 fine

2. Having one's car towed and impounded.

3. Being brought to Hiko, Nev., to be processed.

"Once released, you will be responsible for transportation to your next desired travel location," the sign reads.

As a visitor got closer to the gate, all of the surveillance cameras turned nearly in unison to focus on the tour group. Flashing red lights on the gate also started to illuminate.

"It's crazy that you're just standing here and that's Area 51 over there," Jasmeena Samrai told Fox News. "It's a surreal experience. It's an experience like a movie."

CLICK HERE FOR THE FOX NEWS APP

The tour passed an unmarked semi-truck and trailer heading inbound toward the gate. The driver covered his face with his hands as he drove by.

The Internet joke about storming the mysterious location has spurred two rural Nevada counties to draft an emergency declaration, with local law enforcement planning to pool resources with the state and neighboring counties ahead of Sept. 20-22 events.

During the day on Wednesday, numerous emergency vehicles could be seen heading north along U.S. 93 toward the site, and staging areas could be seen with fire and rescue personnel.

Alien-themed festivals have spurred officials to have hundreds of law enforcement officers and medics on hand, along with the Nevada National Guard.

Deputies in Nye County last week arrested two Dutch tourists attracted by "Storm Area 51." The men pleaded guilty to trespassing at a secure U.S. site nowhere near Area 51 and promised to pay thousands in fines.

County lawmakers in Nye County, home to a conspicuously green establishment called the Area 51 Alien Center (though it isn't remotely close to an actual entrance) have discouraged people from trying to find any extraterrestrials there.

"We're taking precautions and checking the back roads," Sheriff Sharon Wehrly told The Associated Press Wednesday.

The Associated Press contributed to this report.