ap photo Vehicles line up in a several hour wait to leave the Burning Man festival in Black Rock Desert, Nev., Tuesday, Sept. 5, 2023. The traffic jam leaving the festival eased up considerably Tuesday as the exodus from the mud-caked Nevada desert entered a second day following massive rain that left tens of thousands of partygoers stranded there for days.

RENO, Nev. — The traffic jam leaving the Burning Man festival eased up considerably Tuesday as the exodus from the mud-caked Nevada desert entered another day following massive rain that left tens of thousands of partygoers stranded for days.

A pair of brothers from Arizona who took their 67-year-old mother with them to Burning Man for the first time spent 11 hours into early Tuesday morning just getting out of the festival site about 110 miles north of Reno.

“It was a perfect, typical Burning Man weather until Friday — then the rain started coming down hard,” said Phillip Martin, 37. “Then it turned into Mud Fest.”

Event organizers began letting traffic flow out on the main road Monday afternoon — even as they urged attendees to delay their exit to help ease traffic. The wait time to exit Black Rock City was about 3.5 hours as of Tuesday at about 5 p.m., according to the official Burning Man Traffic account on X, formerly known as Twitter.

Roughly 36,000 people remained at the site Tuesday by mid-afternoon, organizers said.

The annual celebration of free spirits in one of the most remote places in America launched on a San Francisco beach in 1986 and has since grown in size and popularity. Nearly 80,000 artists, musicians and activists visit the Black Rock Desert every year to build a city of colorful themed camps, decorated art cars and guerilla theatrics in preparation for the ceremonial burnings of a towering, faceless effigy and a temple dedicated to the dead.

Most attendees travel to the stark desert for a week to express themselves with music and art, commune with nature, or “find themselves.” Others visit the ancient lake bottom for a psychedelic party full of hallucinogens and nudity before the burning of the wooden effigy.

The event this year began Aug. 27 and was scheduled to end Monday morning, with attendees breaking down camps and cleaning up — until the rains came.

After more than a half-inch of rain fell Friday, flooding turned the playa to foot-deep mud — closing roads and forcing burners to lean on each other for help.

Burning Man emphasizes self-sufficiency, and many burners arrive in Black Rock Desert with limited supplies, expecting to face challenges in the form of brutal heat, dust storms — or torrential rains.

Disruptions are part of the event’s recent history: Dust storms forced organizers to temporarily close entrances to the festival in 2018, and the event was twice canceled altogether during the pandemic.