Erin Carson/CNET

They came in peace. Crowds stayed calm and controlled on the first official day of the Alienstock festival in Rachel, Nevada. What started as a viral Facebook event to storm the gates of Area 51 and morphed into multiday gathering in rural Nevada, proved what many familiar with Facebook invites know: Just because someone marks "interested," that doesn't mean they're going to show up.

Though local residents and officials were concerned that an unknown number of attendees (30,000? 50,000?) could engulf what's otherwise a town of about 50 -- with no gas station or streetlights -- the area was far from mobbed. Instead, the crowd was perhaps 3,000, Lincoln County Sheriff Kerry Lee told the Associated Press.

Friday, there were no miles-long traffic snarls or empty-tanked cars by the side of the road. The parking lot for cars was mostly open, and there was a smattering of tents and campers alongside the road. The main stage, at one point, had an audience of three. And though the medical team on site declined to comment, by early midday Pacific time, they were sitting around the First Aid tent, unoccupied. Meanwhile, Nevada Highway Patrol tweeted that a car collided with a cow (cattle wander freely in the area). The cow didn't make it.

This event, which is actually one of three scheduled for Las Vegas, Rachel and Hiko, initially grew out of a Facebook event that went viral in July. Bakersfield, California, resident Matty Roberts created the event titled "Storm Area 51, They Can't Stop All of Us" as a meme page.

Roberts told CNN he got the idea after listening to an interview on Joe Rogan's podcast with filmmaker Jeremy Corbell and Bob Lazar, who says he worked at Area 51 in the '80s. Lazar is the subject of Corbell's documentary, currently on Netflix, Bob Lazar: Area 51 & Flying Saucers. By the end of July, 2 million people had RSVPed for the event, whose description was: "We will all meet up at the Area 51 Alien Center tourist attraction and coordinate our entry. If we Naruto run, we can move faster than their bullets. Let's see them aliens."

Those 2 million folks in question left Lincoln County budgeting $250,000 to deal with the potential chaos in Rachel and Hiko, the Las Vegas Review Journal reported.

Though no giant hoard of people turned up wanting to free aliens from Area 51, festivalgoers seemed content with the event.

"So far it's turned into exactly what we thought it was going to be like," said Analisa, a Sacramento resident who asked to be identified by first name only. "I didn't expect a whole lot, except something cool in the middle of nowhere."

Jesus Bravo took the day off work and came in from Carson City, Nevada, after following the event page. When asked if Alienstock was living up to his expectations, he said, "It's more. I literally thought it was just going to be a group of people in the middle of the desert -- not as big, and with vendors." Bravo also said he appreciated meeting so many attendees from different places outside Nevada.

"It seemed like it was going to be a good time, we'd have a lot of fun, and there was nothing going on today," said Christopher Reid, a Reno, Nevada, resident who drove down last minute with a friend to make tinfoil hats for attendees for fun.

And one participant explained to another that he was there with his grown son as a father-son outing.

Justin and Christopher are out here making tin foil hats for folks for free. A public service, Christopher tells me. #AlienStock #Area51 pic.twitter.com/VuySbOiX3R — Erin Carson (@ErinCarson) September 20, 2019

Although the day stayed relatively calm, local residents Bob Clabaugh and Pat Jordan, both retired pilots, expressed concern that Alienstock will become a recurring event, bringing bigger and bigger crowds to little Rachel every year.

In the residential section of Rachel, people invested in floodlights, which they've never needed before, and plastered up No Trespassing signs. One house put up signs that said "No Alien Stock" and another that said "Go home."

Still, attendees, milling about and fielding questions from a growing group of reporters, seemed to be enjoying the novelty of the happening, even if there wasn't much to do.

One gave a solid thumbs-up -- apart, that is, from the moment when he was abducted by little green men and subjected to the legendary examination.

"If not for the probing last night," he quipped, "it would have been a great weekend."

Now playing: Watch this: What it's like going to a Naruto run

Originally published Sept. 20, 7:35 p.m. PT.

Update, Sept. 21: Includes additional information, about crowd size and collision with local cow.