Los Angeles County Sheriff Alex Villanueva said the "super-spreader" event, which was held in a vacant home in Palmdale on Saturday, was also the site of alleged underage trafficking.
Los Angeles County deputies arrested 120 adults and 38 juveniles at the party, all of whom were issued citations for violating health orders, authorities said. Among those arrested, five people were also charged with burglary, one with possession of a firearm and one with obstruction. The "entire organizing network" of the party -- three 18-year-olds and two 17-year-olds -- was arrested, authorities said.
Deputies recovered six firearms and were able to rescue a 17-year-old human trafficking victim, Villanueva added.
A rental truck with video equipment was found at the scene, authorities said. "This is how brazen this operation was," Villanueva said.
The sheriff's department is targeting these types of "super-spreader events," as opposed to restaurants and businesses that violate county and state health orders, Villanueva said.
"We don't have unlimited resources," he said. "This is something that is worth spending our resources to clamp down on because these super-spreader events, if we get rid of them, we're going to improve our ability to fight the pandemic on a whole scale."
At least half a dozen of these types of events occur on a "weekly basis" on weekends, Villanueva said. The organizers of this event allegedly promoted parties in Pomona and Ontario over the weekend, he added.
It is unknown at this time if anyone arrested this weekend has tested positive for COVID-19, officials said Tuesday.
The bust comes as Los Angeles County is reporting record COVID-19 cases and hospitalizations. The five-day average for daily new cases is 8,993 -- nearly double what was reported the day after Thanksgiving, health officials said.
Last month, the county issued a temporary stay-at-home order and banned outdoor dining amid the surge. The county is now under a state-issued stay-at-home order after the Southern California region's available intensive care unit capacity dipped below 15% on Saturday. Both orders prohibited gatherings with people outside one's household.
ABC News' Alex Stone contributed to this report.