Pershing County Sheriff's Department said the unnamed woman was "fatally struck by a bus," although the exact circumstances of her death remained unclear. The woman's name was expected to be released once the sheriff's office contacted her next-of-kin.
Burning Man promoter Jim Graham said the woman died just after midnight in the Central Camp area.
"This is a terrible accident," said Burning Man co-founder Marian Goodell. "Our thoughts and prayers are with her family, friends and campmates. Black Rock Rangers and Emergency Services Department staff are providing support to those affected."
There hasn't been a death at Burning Man since 2007, when a woman died when she fell under a trailer being pulled by a bus, Graham said.
About 68,000 people attended this year's annual Labor Day week event in the Black Rock Desert. The event describes itself as a dedication to "the spirit of community, art, self-expression and self reliance."