Determined to check out one final tip about the climbers missing on Mount Hood, Sheriff Joe Wampler piloted the department's Piper Cub toward the 11,239-foot peak.

He found that what a snowshoer had thought was a yellow tent in the distance was, upon closer inspection, just a rock.

So the Hood River County sheriff landed his plane and told reporters Wednesday that he was calling off rescue operations. He said the new focus would be on "recovery," which in the parlance of search and rescue means a hunt for bodies.

"The chance of survival is pretty nil. I don't think I can justify putting any more people in the field with the hope of finding them alive," Wampler said.

Despite the punishing storms, rescue crews had headed into the mountain soon after Kelly James of Dallas used his cell phone on Dec. 10 to tell his family that he and two companions were in trouble.

Searchers found James' body in a snow cave Sunday, several days after he had died of hypothermia, according to the results of an autopsy Wednesday.

Wampler said planes would be sent out to look for the two climbers who remain missing, but history and mountain experts suggest it might be spring before Brian Hall of Dallas and Jerry "Nikko" Cooke of New York City are found.

Some members of the Hall and Cooke families agreed that the search should end, the sheriff said.

"We wouldn't be doing this today if they hadn't been part of that decision," Wampler said at an airfield news conference.

What happened on the mountain is a matter of conjecture based on James' telephone call, photos taken by the climbers, and such evidence as two ice axes and a climbing harness found by search crews.

Authorities say James might have been injured in a fall, prompting Hall and Cooke to go for help. The two climbers then might have fallen or been blown off a cliff, buried by an avalanche or died of hypothermia.

Morale among searchers had been high, buoyed by pizzas sent by the climbers' families and socks by local businesses, the sheriff said.

But most of the volunteer mountaineers who helped find James and recover his body had returned to their workaday lives by Tuesday. National Guard helicopters also had returned to their bases.

Wampler said the search had been risky, including operations near the summit where rescue teams located James' body and climbers and military personnel winched it off the mountain.

The three experienced climbers had planned on a quick, lightly equipped ascent on Mount Hood. But a quick climb in December is shortsighted, the sheriff said.

"A minimum climb this time of year is three days, not just one day, three days," Wampler said. "You plan on having to stay out there in case something happens."