LAS VEGAS, Nev. – Commissioners in Nevada's rural Lincoln County have voted to pre-sign an emergency declaration ahead of the "Storm Area 51" raid event that's so far drawn more than 2 million RSVPs on Facebook.

On Monday, the county board unanimously voted, 4-0, to approve the declaration in preparation for a mysterious affair that could draw thousands of curious visitors to the desert.

"We passed this with the caveat that this may or may not happen," said District D Commissioner Kevin Phillips. "We're just trying to do the best we can to prepare for something we know not of. We have no pickin' idea what we're going to face – if anything."

California resident Matty Roberts created the event – called "Storm Area 51, They Can't Stop All of Us" – in June after listening to an episode of the Joe Rogan Experience podcast. The tongue-in-cheek event scheduled for Sept. 20 quickly generated millions of accepted invitations.

Lincoln County is home to the town of Rachel, the self-proclaimed "UFO Capital of the World," located on State Route 375 – dubbed in 1996 the "Extraterrestrial Highway."

The actual Area 51 site is a classified military facility set inside a test and training range roughly the size of Connecticut. Intrigue surrounding the impenetrable desert compound for decades has fueled conspiracy theories and local lore about what exactly goes on there.

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But it’s a mystery that’s now driving an unknown number of unknown people from unknown corners of the country to the Nevada hinterlands. Lincoln County leaders are using this preemptive emergency declaration as a beacon to state officials that there’s a chance more people will show up than local authorities can handle.

An emergency declaration allows the state to supply resources in the event the outpost of 5,200 people needs help.

"It's a smart chess play," Phillips said.

Air Force spokeswoman Laura McAndrews said in a statement to USA TODAY that military officials were aware of the event that aims to uncover what many people believe are conspiratorial secrets of the military installation in Nevada.

McAndrews didn't specify any security plans at the base, but she did warn those thinking of entering the area.

"The Nevada Test and Training Range is an area where the Air Force tests and trains combat aircraft," McAndrews said. "Any attempt to illegally access military installations or military training areas is dangerous."

Follow Ed Komenda on Twitter: @ejkomenda.