Wyoming authorities said Monday they are awaiting toxicology tests to help determine the cause of death of Petaluma rodeo star Broc Cresta, who was found dead in his trailer Saturday after competing in the Cheyenne Frontier Days Rodeo.

Funeral services are scheduled for 4 p.m. Friday at Santa Rosa's Wells Fargo Center for the Arts, the rodeo association announced. Further details were unavailable Monday.

Laramie County Coroner Marty Luna said an autopsy performed Saturday showed no trauma or other clear reason why Cresta, age 25, died in his sleep.

"There was nothing obvious in the autopsy that would have given the pathologist any conclusions into the cause and manner of his death," he said. "It's just hurry up and wait now for the toxicology tests."

Normally those tests take as long as six weeks to return, Luna said, but he asked the lab to expedite them.

Cresta, a Santa Rosa High School graduate, was a team roper who had competed in the National Finals Rodeo the last two years. He was found dead Saturday in his living quarters trailer at the Cheyenne Frontier Days Rodeo, the Professional Rodeo Cowboys Association said.

Cresta's team-roping partner and longtime friend, Spencer Mitchell, said the two had competed Friday, then shared a beer at Cresta's trailer afterward. Cresta had then left to watch a concert with his girlfriend, champion barrel racer Brittany Pozzi.

When Mitchell visited Cresta Saturday morning, he and Pozzi were asleep. She soon emerged from the trailer and chatted with Mitchell, then tried to wake Cresta.

Cresta, apparently in good health just hours earlier, was pronounced dead.

The autopsy revealed no signs of foul play or trauma that may have been lingering from a rodeo injury, Cheyenne Police Department Sgt. Rob Dafoe said.

"There wasn't any outward sign that we would consider an automatic criminal event," he said. "They're still looking into what happened in his last few hours, what happened the evening before."

He said they were "confident alcohol was involved," but unsure as to the extent.

"Whether he was toxic or whether that created some other event, it will be up to the coroner," he said. "For the most part, it's a waiting game."

He said police were continuing to interview witnesses and had searched the trailer to see if any other evidence surfaced to explain Cresta's death.

While rodeo can be a dangerous sport, deaths have been relatively rare, said Jim Bainbridge, a spokesman for the Professional Rodeo Cowboys Association.

"Everyone is just kind of stunned," he said Monday. "Anytime one of these things happen, it's a feeling of disbelief — someone in perfect health one minute and is gone the next."

There was no indication Cresta had been injured in the competition on Friday, Bainbridge said. The last time a cowboy died at Frontier Days was in 1989, when Lane Frost died after being hooked by a bull. A vehicle crash last year killed a young steer wrestler and two years ago, Bainbridge said, two cowboys died of carbon monoxide poisoning in their camper.

Cresta, a Petaluma resident, grew up riding ponies and roping on his family's 500-acre ranch, west of Santa Rosa on Mark West Springs Road. His parents, Dan and Kelline, owned Mexican Corriente cattle and organized roping events all over California.

When Cresta was 9, he started tossing a rope around an assortment of animals — ponies, donkeys, horses and goats — in the rodeo ring on the ranch. By the time he reached high school, he was missing so much school to compete in rodeos that he switched to an independent study program. He graduated from Santa Rosa High School in 2005 and turned pro two years later.

Following in the footsteps of his father, he emerged as a talented roper at an early age. His father and uncle wrestled steers on the pro circuit. His grandfather, William, raised horses for the sport and owned a champion steer wrestling horse.

Cresta traveled 60,000 miles a year to compete in rodeos across the country. With his team-roping partner he won several rodeos in California this year, in Redding, Livermore, Oakdale, Bakersfield and Marysville, and one in Eugene, Ore. He withdrew from a rodeo in Oklahoma City three months ago when he injured his ribs but was otherwise healthy, his father told the Los Angeles Times.

Cresta was the 2007 PRCA Rookie Heeler of the Year, and he competed in the past two Wrangler National Finals Rodeos. At the time of his death, Cresta was ranked 14th among heelers in the world team-roping standings, the highest-ranking Californian. He finished 12th overall in 2011.

In addition to his parents and grandfather, he is survived by a brother, Brent, of Cloverdale.

Los Angeles Times and the Associated Press contributed to this report.. Contact Staff Writer Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com.