Searchers found no sign on Sunday of a single-engine plane believed missing in the northwest Wyoming mountains with a Minneapolis man and three of his sons aboard.
The Mooney 20J took off from the Jackson airport in a snowstorm on Oct. 25 and disappeared from radar about an hour later. The plane was bound for Riverton, Wyo., and then Minneapolis.
The pilot was Luke Bucklin, 40. His 14-year-old twins Nate and Nick and 12-year-old Noah were also aboard.
The search is centered on nine square miles of rugged terrain east of Gannett Peak, the highest in Wyoming at just over 13,800 feet. Crews have been searching in an area of steep canyons.
A search plane detected a signal on Thursday that officials thought was coming from the missing plane's emergency locater.
Jason Aanestad, the search operations chief, said Sunday the Civil Air Patrol would try to re-evaluate the signal.
Two ground teams spent Saturday night in the search area because weather conditions kept helicopters from retrieving them.
A helicopter did get a third crew out of the area. Members of that team reported blizzard-like conditions.
The weather improved Sunday.
Bonnie Harris, a friend of the Bucklin family, said they had been in Wyoming for a wedding and family vacation. Luke Bucklin's wife, Ginger Bucklin, and the couple's youngest son flew home separately on a commercial flight, Harris said.
Luke Bucklin is president and co-founder of the Bloomington, Minn.-based Web development company Sierra Bravo Corp.
Harris said Bucklin received his pilot's license in 2002.