Federal investigators spent much of Sunday at the cordoned-off wreck site, where a Hughes 369 chopper went down Saturday, about a mile west of the Carbon County Airport, northeast of Price.

Killed were James Ian Innes, 59, of Salt Lake City; his son Andrew Innes, 30, of Park City; and George McDaniel, 40, of Idaho Falls, Idaho.

Friends of James Innes, pilot of the downed helicopter, say he was an icon in wildlife-relocation in New Zealand and in the U.S. He and his son were originally from New Zealand.

The three men were returning from a fishing trip with seven other friends on the Range Creek when their chopper crashed.

Jeremy Johnson, who was piloting another helicopter with the group, said his copter lifted without problems. His companions' helicopter lifted off, but Johnson looked away and when he looked back, he did not see it. He also could not reach it on radio, he said.

Innes was an experienced pilot, Johnson said, but the helicopter may have been carrying too much weight. He said flying in and around Price is challenging because high temperatures and altitude cause thin air, which puts a strain on copters. The airport sits about 5,700 feet above sea level.

Patrick Jones, an air-safety investigator, would not speculate Sunday on the cause of the crash, but said high temperatures make it more difficult for all kinds of aircraft to fly. He said temperature, air pressure and altitude can affect how well an airplane's wing - or a helicopter's rotor - generates lift needed to keep the craft airborne. The high temperature the day of the crash was 96 degrees Fahrenheit, according to the National Weather Service.

Jones said investigators would be moving the wreckage in the next two days for further study. He said a preliminary report will be available within five to 10 days. That report will only list the facts about the accident, Jones said. Other investigators will go over the report and determine what actually caused the crash.

It's the second fatal crash near the airport in the past 13 months. In June 2007, two people died when their plane struck power lines.

Carbon County Sheriff James Cordova said the fire at the copter crash was confined to the site, where a piece of the chopper's tail section and part of its rotors rested on the charred ground Sunday. He restricted flights over the site until Sunday afternoon, when the men's bodies were taken away and reporters were allowed to see the wreckage.

Cordova quickly ruled out wind gusts as a factor in the crash. "The weather was just like it is now," Cordova said, as a gentle breeze blew across the crash site. "It was a little warmer then, but it wasn't gusts of wind."

James and Andrew Innes were born in New Zealand and had developed a thriving wildlife-relocation business there, said Marc Bingham of Orem, who was on the fishing trip and owned the helicopter James was piloting. James developed a new breed of sheep embryo and at one point had a large ranch in New Zealand, he said.

The father-and son team later expanded their work to the United States where they would transport wild animals per government request to other states, moving wolves out of Yellowstone National Park and buffalo out of American Indian reservations, Bingham said.

Friends and New Zealand news organizations reported that Andrew Innes recently married. "Andrew had a real good job, just bought a new car," said Woods Cross friend Charles Ward, director of flight operations with helicopter company Pathfinder. "A real nice kid. He had his act together."

His death marks the second for the family. Andrew's brother, Dan Innes, was killed when the helicopter he was flying crashed while he was capturing wildlife in Mexico earlier this decade, Bingham said.

"People think that they were just yuppies with money, but they were more than that," Johnson said of the Inneses. "They were successful people, but they were also really adventurous. James loved going places. He was kind of a free bird."

McDaniel, the third man to perish in the crash, was a longtime friend of James Innes. McDaniel's neice, Melissa Holm, said he was a wonderful businessman and father to his two children, Mariah, 16, and Stafford, 14. He owned and operated Foothill Properties, a real estate business.

Holm, who is the director of operations at the company, said George had an extreme life outside of work and loved to snowmobile and ride motorcycles.

"He was a wonderful person, loved by all of us. He was a very generous being. " Holm said. "We're deeply going to miss him."

Funeral arrangements for the three have not been set.