Burning Man flooding strands tens of thousands, 1 dead

An unusual late-summer storm has turned a week-long counterculture festival into a sloppy mess with tens of thousands of partygoers stuck in foot-deep mud and with no working toilets in the northern Nevada desert.

The annual gathering in the Black Rock Desert north of Reno attracts nearly 80,000 artists, musicians and activists for a mix of wilderness camping and avant-garde performances.

More than 1cm of rain fell at the festival site on Friday, the National Weather Service in Reno said, with more coming on Saturday and Sunday.

Organisers closed the festival to vehicles after one death was reported. Officials provided no details of the fatality.

The closures came just before a large wooden effigy was supposed to have been burned on Saturday night. Organisers said that all burning had been postponed, and authorities were working to open exit routes by the end of the Labor Day weekend.

Officials said late on Saturday they didn't yet know when the roads would "be dry enough for RVs or vehicles to navigate safely", but they were hopeful vehicles could depart by late Monday if weather conditions improved.

US President Joe Biden told reporters in Delaware on Sunday he is aware of the situation, including the death, and the White House is in touch with local officials.

With their party closed to motorised traffic, attendees trudged through mud, many barefoot or with plastic bags on their feet. Revellers were urged to conserve supplies of food and water and most remained hunkered down at the site.

A few, however, managed to walk several kilometres to the nearest town or catch a ride there.

DJ Diplo posted a video to Instagram on Saturday evening showing him and comedian Chris Rock riding in the back of a fan's ute. He said they had walked nearly 10km through the mud before hitching a ride.

"I legit walked the side of the road for hours with my thumb out," wrote Diplo, whose real name is Thomas Wesley Pentz.