A 19-year-old Petaluma woman who was last seen leaving a Lake Tahoe music festival around midnight New Year's Eve was found dead in a snowdrift Friday, authorities said.

Alyssa Byrne's death does not appear to have been the result of foul play, said Sgt. Pat Brooks, a spokesman for the Douglas County, Nev., Sheriff's Department.

Byrne disappeared after attending the SnowGlobe Music Festival on New Year's Eve. A utility worker found her body about 8:30 a.m. Friday, Brooks said.

The festival was being held at Lake Tahoe Community College in South Lake Tahoe, and Byrne was staying at the Horizon Casino Resort in Stateline, Nev. Brooks said it appears Byrne set out walking along Pioneer Trail from the concert site and fell into a snowdrift, where her body was hidden from sight for more than three days.

A cause of death has not been determined, but no foul play is suspected, Brooks said. The El Dorado County coroner will perform an autopsy.

The Horizon hotel is 3 miles from South Lake Tahoe, and Brooks said Byrne's body was found a mile from the concert site. Byrne had told friends she was going to take a shuttle from the music festival back to her hotel, but it appears she decided to walk instead, investigators said.

"There were transportation issues at the event," Brooks said. "There were quite long lines of people who attended the event. (Some) elected to walk back instead of taking the shuttle buses. Our preliminary investigation would tend to point in that direction."

Organizers of the festival issued a statement saying, "This is an ongoing investigation and we are working with local authorities to learn more."

No snow fell the night of the festival, but temperatures hovered between zero and 1o degrees, Brooks said. Byrne was wearing a black sweatshirt, black yoga pants and snow boots when her body was found.

"What caused her to leave the roadway and go up and over the berm, I do not know," Brooks said.

Initial reports that Byrne was last seen early New Year's Day in the bar of her hotel were apparently wrong, Brooks said.

Investigators said two messages were posted on Byrne's Twitter account on New Year's Eve. One read, "After tonight you'll never be apart of my life you won't be a memory of 2013 a new year you'll never be apart your nothing to me."

The most recent message was, "Just lost trust in the person I trusted most."

Brooks, however, said investigators do not believe the tweets were related to Byrne's death.

Byrne graduated in 2011 from Casa Grande High School in Petaluma. She worked at Cattlemens steak house in Petaluma and was studying to be a paramedic and firefighter at Santa Rosa Junior College.

Byrne lived with her parents in Petaluma, and her father, other relatives, friends and volunteers joined law enforcement officers in searching the Lake Tahoe area for her. Her mourning family thanked people Friday for their efforts.

"Some families go years and years without knowing" the fate of missing people, said Byrne's great-aunt, Dolores Bruns.

Bruns said Byrne was a "strong, confident young lady, a happy person with a great personality. She will be sorely missed by everybody."