RACHEL, Nevada (Reuters) - Connie West, co-owner of an alien-themed motel in the tiny U.S. desert outpost of Rachel, Nevada, believes they are coming no matter what. Not aliens, but alien hunters.

A whimsical invitation on Facebook has urged UFO enthusiasts to gather on Sept. 20 and “storm” nearby Area 51, a U.S. military base long rumored to house extraterrestrials and spaceships. More than 2 million Facebook users have said they plan to go.

Residents of Rachel, a 150-mile (240-km) drive from Las Vegas and home to roughly 50 people, are split on how to respond. Some sternly warn the public to stay away, fearing large crowds will overwhelm a town with no gas station or grocery store. Others, including West, believe the best course is to welcome them with a music festival dubbed Alienstock.

“We’re trying to figure out how to make this a positive from an absolute negative,” West said in an interview. “You can fight it, but it’s coming.”

West, with her mother, runs Rachel’s only business, the Little A’Le’Inn motel and restaurant, and was inundated with phone calls as soon as the Facebook post appeared. She estimates at least 30,000 people will arrive on Sept. 20, and she’s scrambling to order enough portable toilets. As of mid-August, she had secured 30.

Area 51 was shrouded in secrecy for decades, stoking conspiracy theories that it housed alien bodies and a crashed spaceship from Roswell, New Mexico. The U.S. government did not confirm the base existed until 2013, when it released CIA archives saying the site was used to test top-secret spy planes.

The documents made no mention of little green men or flying saucers, but that did not end suspicion.

Rachel and its surroundings had long celebrated their spot in UFO lore as a tourist draw. A 98-mile (158-km) road running through the area is dubbed the Extraterrestrial Highway, a purported hotbed of UFO sightings.

But when a Facebook user named Matty Roberts from Bakersfield, California, invited people to run into Area 51 on foot in a large group “to see them aliens,” the Air Force cautioned against it.

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“Any attempt to illegally access military installations or military training areas is dangerous,” an Air Force statement said in response to questions about the event.

The Air Force said it uses the facility to test combat aircraft and train personnel. The entrance is dotted with cameras and signs warning against trespassing.

CONCERNS ABOUT CRIME AND CATTLE

Now, Roberts is trying to draw people instead to Alienstock, a three-day music festival in Rachel. West said she gained permission from local property owners to fence off 30 acres (12 hectares) for festival camping and parking, and she made arrangements to bring in a water truck plus hire security personnel and paramedics.

A website is selling Alienstock parking and campsite permits but does not list any performers. Roberts did not respond to requests for comment, but locals have plenty to say.

“There’s a group of us concerned residents that really do not want this even to happen,” said Joerg Arnu, who runs websites on the history of Rachel and Area 51. “It’s going to destroy Rachel as a beautiful small town in the desert.”

Arnu called on authorities to shut down the two-lane road that leads into town to keep people away during that time.

Townspeople worry, he said, that visitors will include “a fair number of crooks” and that crowds will damage property.

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“The residents are going to do whatever it takes, and I’ll leave it at that, to protect their properties,” Arnu added. “We hope it doesn’t come to a confrontation, but if it does it has a very high potential to get ugly.”

He also fears the town’s power lines, cell phone service and Internet connections will go down, and that visitors will run into a local hazard: cattle on the road. Each year, cars collide with cattle because they are hard to see at night, he said.

West urged would-be revelers to bring water, clothing for hot temperatures during the day and cold ones at night, and fuel.

About 40 miles (64 km) away in Hiko, Nevada, a gift shop called the Alien Research Center also plans an event with food trucks, live bands, games and entertainment on Sept. 20 and 21.

Commissioners in Lincoln County, which includes Rachel and Hiko, are taking steps to prepare, including drafting an emergency declaration that can be invoked to call in help from the state.

West said the region had no choice but to embrace the sudden interest in Area 51. Resisting it would fuel more conspiracy theories, she argued.

If local authorities had urged people to stay away, “they were going to think that we had something to hide,” she said, “that we’re in cahoots with the government.”