The mystery of Steve Fossett is most likely solved, but the gray granite peaks of the Sierra Nevada may never give up the secrets they hold of missing aviators and planes wrecked long ago.

Searchers spotted Fossett's battered single-engine plane Wednesday night, more than a year after he took off from a Nevada ranch. Wreckage indicated a high-speed impact at about 10,000 feet. Small pieces of human remains were found with the wreckage, National Transportation Safety Board Chairman Mark Rosenker says.

Madera County Sheriff John Anderson wasn't sure of the remains, the Associated Press reported. "We don't know if it's human. It certainly could be," he says.

The location -- far from the main search areas farther north -- didn't surprise the amateur sleuths who spend years in search of missing planes in these mountains.

"The Sierra probably holds the majority of the airplanes that weren't found for a while due to its remoteness and its ruggedness," says Craig Fuller, who studies plane crashes. He runs a website called Aviation Archaeological Investigation and Research.

Unforgiving terrain

The mountain range, which runs up California's eastern side and has the highest peak in the continental U.S., has been the backdrop of many aviation mysteries.