Swarms of searchers combed the rugged Minaret Range Thursday in hopes of answering the main two remaining questions in the mystery of missing adventurer Steve Fossett: Where are his remains, and what caused his single-engine airplane to slam into a steep granite slope 7 miles west of this town?

The investigation will take months, if not years, but Fossett's friend and fellow aviator, John "Bumper" Morgan, doesn't have to see the crash site in the Inyo National Forest to know what probably happened.

Morgan has flown gliders and airplanes for decades throughout the Eastern Sierra, where the pieces of Fossett's borrowed plane were found this week, and he's come to fear the downdraft of wind coming off the slopes and the sudden thermals whipping up from the ground.

"One of those two things got Steve, I'm pretty sure," said Morgan, 63, of Gardnerville, Nev. "Even if you have your head screwed on straight and are a very good flier like he was, downdrafts and thermals can leap up and get you. Mother Nature just knows how to dish out more than you can handle."

Investigators announced Thurs-day that they had found what might be remains at the crash site and that they could be enough for the coroner to process for identification.

The impact of the crash was so forceful that there wasn't much to work with, they added.