(CNN) -- The Civil Air Patrol has called off the search for multimillionaire adventurer Steve Fossett, nearly a month after he took off from a Nevada ranch, the agency announced Tuesday.
Adventurer Steve Fossett has been missing since September 3.
Fossett, 63, was last seen September 3 when he left hotel magnate Barron Hilton's private Minton, Nevada, ranch in a single-engine plane.
He was reported missing after his Bellanca Super Decathlon failed to return from the flight. Fossett was said to be scouting test sites for a future attempt at breaking the land speed record.
In a statement announcing the end of the effort, the Civil Air Patrol said rescuers covered 20,000 square miles in an effort to locate Fossett -- "one of the largest, most intensive searches for a missing aircraft in modern history."
"The Civil Air Patrol joins the rest of the aviation world and admirers worldwide in its disappointment in not locating Steve Fossett," said Brig. Gen. Amy S. Courter, the agency's acting national commander.
Fossett was the first man to fly around the world in a balloon alone and the first solo pilot to circle the globe without refueling. He holds 14 world records in airplane flight, two for ballooning, six in gliders and one in an airship, in addition to 11 records for sailing and one for cross-country skiing.
"This remarkable man showed us what grit and determination are all about," Courter said. "In his life, he chased and shattered world records, floating and flying farther and faster than anyone before. His adventures are many and his accomplishments profound. We regret that those adventures may have come to an end."
The search was scaled back September 19, but rescuers said they would continue to pursue tips sent by phone and e-mail. E-mail to a friend