Some of those living in the area were glad to hear that the men were directing visitors elsewhere, according to Joerg Arnu, one of the fewer than 100 Rachel residents. “We are very, very relieved,” he said.

Mr. Arnu accused Ms. West of keeping residents in the dark about the event, while Mr. DiMaggio said she did the same to her fellow organizers.

Ms. West did not respond to multiple requests for comment, but said in the KTNV interview on Thursday that she was pleased with the early showing for the weekend event.

“I think I’m on my highest high I’ve ever been in my entire life,” she said. About 250 campsites had been paid for in advance, she said.

A Party of the Third Kind

While the Rachel event was in the works, another group of organizers was planning a gathering scheduled for Friday, Sept. 20, and Saturday, Sept. 21, in nearby Hiko, home to the Alien Research Center, a gift shop.

While that event, the Storm Area 51 Basecamp, is slated to feature food, drink and music, it also includes a lineup of speakers intended to appeal to those interested in aliens and the secretive military base.

“We’re focusing on the true believers, we’re not looking for a rave in the desert,” said Keith Wright, managing partner of Production Specialists of Las Vegas, an events company, and one of the organizers of the Basecamp event.