Authorities said Monday they have positively identified some of Steve Fossett's remains: two large bones found a half-mile from where the adventurer's plane crashed in California's Sierra Nevada.

Madera County Sheriff John Anderson said DNA tests conducted by the state Department of Justice positively identified the bones as the remains of the millionaire aviator who disappeared last year.

Anderson has declined to say what bones were found, saying he didn't want to cause the family further anguish.

Fossett's widow, Peggy Fossett, released a statement thanking authorities for their work.

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"I am hopeful that the DNA identification puts a definitive end to all of the speculation surrounding Steve's death. This has been an incredibly difficult time for me, and I am thankful to everyone who helped bring closure to this tragedy," she said.

The bones were discovered last week, along with Fossett's tennis shoes and Illinois driver's license, which had animal bite marks on them.

Fossett disappeared in September 2007 after taking off from a Nevada ranch owned by hotel magnate Barron Hilton for what was supposed to be a short pleasure flight. Law enforcement, fellow aviators and others launched a costly search that covered 20,000 square miles but turned up empty.

The wreckage of Fossett's plane was discovered last month after a hiker walking off trail in the Sierra Nevada near Mammoth Lakes stumbled across Fossett's pilot's license and a wad of weathered $100 bills. Authorities said Fossett likely died on impact.

The National Transportation Safety Board is investigating the cause of the crash.