The situation is becoming increasingly troubling as searchers for Steve Fossett continue into their fifth day.
While throughout their search they have found remains of six other plane crashes from years ago, they are no closer to solving the mystery of what happened to Fossett.
The 63-year-old millionaire adventurer has been cheating death his whole life, so it is especially difficult for those involved to imagine he may actually have lost this time -- particularly since he was just flying a routine flight.
No one has seen Fossett since around 9 a.m. Monday, when he took off in a single-engine aircraft from a private air strip on a ranch southeast of Reno called Flying M, owned by his friend, the hotel magnate Baron Hilton.
The flight was supposed to take three hours, Fosset was scouting locations for his latest stunt attempt, to break the world's land speed record. No one has heard from him since.
The flight was so routine that Fossett didn't even file a flight plan, and that is why searchers are having such a difficult time, because they have no idea where to look. They have been scouring a massive area, around 17,000 square miles.
It's like "looking for a very small needle in a very large haystack," said Civil Air Patrol Maj. Cynthia Ryan. "We are just scratching the surface."
About two dozen aircrafts are canvassing Nevada's rugged mountains and steep canyons for any sign of clues. They include airplanes, helicopters and a C-130 cargo plane.
The C-130 soars more than 10 times as high as the smaller search planes. The height allows the crew, using high tech cameras, to scan large swaths of land.
"Our cameras are so good we can look at a larger area much faster -- and that's the synergy of having the small planes below us and us up above," said Capt. Col. Jon Pruehl, who has also searched for missing climbers on Mount Hood and over the floodwaters of Katrina.
It is hard for him to grasp how a veteran flier such as Fossett could have disappeared.
"The plane looked like it was fairly new, well maintained, [with an] experienced pilot," Pruehl said. "It's really baffling."
The Nevada Army and Air National Guard combined have spent about $180,000 so far on the search for Fossett. Officials for the Nevada Highway Patrol and Civil Air Patrol said they don't know how much their agencies have spent.
Undersheriff Joe Sample from Lyon County, Nev., is in touch with Fossett's wife Peggy and personal pilot who remain at the Flying M Ranch in Yerington. He called them hopeful, but subdued.
"They are having a tough time with this," he said.
But friends and family say if any one can survive in the rugged Nevada wilderness it is Fossett, who has accomplished feats few would ever dare attempt, including sailing alone across the Pacific, climbing the world's highest mountain peaks, running the Iditarod and racing in the LeMans Grand Prix.
Fossett quit his job as a commodities broker and went on to break more than 100 world records. In 2002, he tackled one of the last unattained goals of human exploration -- becoming the first person to fly a balloon around the world alone. It took him five tries to break the record, and he endured a harrowing close call when his ripped balloon plummeted 30,000 feet into the Coral Sea.
In 2005, Fossett fought through sleep deprivation and severe turbulence to set another mark -- the longest non-stop solo flight in history. It was a 76-hour voyage that ended with a last-gasp emergency landing.
Now it's looking his most routine of flights may have turned out to be the most challenging.