Updated

The search for a missing 19-year-old California woman who disappeared on New Year's Eve at Lake Tahoe ended Friday when her body was found behind a snow bank about a mile from the site of a music festival she attended that night, authorities said.

Alyssa Byrne of Petaluma may have tried to walk three miles in freezing weather to the hotel where she was staying, and became disoriented or lost, Douglas County Undersheriff Paul Howell said. Her body was found along a road.

The cause of death has not yet been determined, but neither foul play nor suicide is suspected, he said.

Howell noted other concertgoers decided to walk back to a hotel in Stateline, a tourist destination on Lake Tahoe's south shore, because there were long lines for shuttle buses.

Nighttime temperatures have plunged to zero in the area in the past week, with daytime highs still well below freezing.

"If exposed to the elements you could succumb to that," Howell told The Associated Press. "We won't speculate on that (hypothermia) as the cause of death, but we're hoping to get an answer from the autopsy."

The autopsy also will determine whether alcohol or drugs were a factor, he said.

A utility worker found Byrne's body around 8:30 a.m. Friday along Pioneer Trail, a major thoroughfare on Tahoe's south shore, Douglas County Sheriff's Sgt. Pat Brooks said. Her body was just off the roadway but obstructed from view by the snow bank.

The discovery was made about one mile southeast of the festival venue at Lake Tahoe Community College, while the Stateline hotel-casinos are some three miles east of the campus. Tens of thousands of young revelers gather in the area annually to ring in the new year.

Byrne was in South Lake Tahoe with friends over the holiday to attend the SnowGlobe Music Festival, which drew 40,000 people over a three-day run. They were staying at the Horizon Casino Resort in Stateline.

Friends told authorities that they last saw Byrne in a bar at the resort between 12:30 and 1 a.m. Tuesday. While her friends returned to the hotel from the concert, Byrne did not, Howell said, adding it's not unusual for friends to become separated at major events.

Cellphone records show her last call that night was made from the vicinity of the concert, Howell said.

"We know she left the event, but we don't know where she was last seen," Howell said. "We'll talk to people who thought they saw her, and try to determine what led to her death."

Byrne's disappearance prompted a dayslong effort by search and rescue teams, friends and family members, who put up flyers and urged anyone with information on the young woman's whereabouts to come forward.

Byrne was taking classes at Santa Rosa Junior College's Petaluma campus to become a firefighter and worked as a hostess at Cattlemens restaurant in Petaluma.

A female employee at the restaurant said she was asked not to talk to the news media and referred inquiries to her manager, who didn't immediately return a request for comment. A woman who answered the phone at Byrne's Petaluma home also declined to comment, saying "We're not taking any calls now."

The music festival website urges concertgoers to be prepared for cold temperatures, and not to attempt to walk or hitchhike to and from the event.

Parking is prohibited at the festival, and attendees must buy a pass for shuttle bus service for transportation, the website says.

Festival producer Chad Donnelly told the Tahoe Daily Tribune that he plans to refine the shuttle service and develop ways to shorten the lines that formed at security, but overall the event went as predicted.

While the festival tilts heavily toward electronic dance music, it features an eclectic mix of entertainment, including rap, hip-hop and electro-funk.