Mount Hood, Ore. ? Hope that three stranded climbers would be found alive continued to fade Saturday after more than 70 airborne and snow-shoed rescuers swarmed the jagged slopes of Mount Hood.

Military helicopters and airplanes outfitted with heat sensors swooped over the mountain’s northern face looking for thermal signatures of life. They found nothing.

Despite Saturday’s lack of success, rescue officials tried to remain positive.

“These climbers were well-prepared … and experienced,” said Sean Collinson of the Clackamas County sheriff’s office. “That gives us a great deal of hope.”

A C-130 cargo plane would continue to fly overnight looking for body heat, he said. The best time to identify missing climbers is early in the morning when their radiant heat stands out against the cold mountain.

Family members offered a resolute, optimistic message Saturday morning at their first joint news conference.

Clara Hall, mother of 37-year-old Dallas climber Brian Hall, said she finds comfort in a pact she has with her son. Even when he is gone, they will look up at the same moon.

“Last night,” she said, “I saw the moon.”

Lou Ann Cameron, mother of 48-year-old Dallas landscape architect Kelly James, said: “I know my son’s coming down today. It’s my birthday. He wouldn’t miss my birthday.”

Jerry “Nikko” Cooke, a 36-year-old Brooklyn attorney, is the third missing member of the expedition that has been stranded a week on the 11,239-foot mountain.

Other than a flurry of hopeful midday radio traffic when a helicopter spotted two forms it suspected were climbers, rescuers were bedeviled by bitter cold and blowing snow Saturday. The dark forms seen against the icy slope were probably rocks.

Ground rescue crews made it to about 10,000 feet on the north and side of the sleeping volcano Saturday afternoon before retreating down the mountain because of harsh weather and impending nightfall.

“It wasn’t quite the dream picture we had hoped for today,” Sgt. Collinson said, describing high-altitude 50 mph wind gusts and blowing snow. “But there is the chance tomorrow will be a better day.”

Officials deflected questions about when the rescue would become a recovery mission, but Hood County Sheriff Joe Wampler said the effort would continue through today.

“We’d like to do it through the weekend,” he said. “We’re still optimistic.”

New information about the climbers’ provisions lifted hopes Saturday.

According to a note that the men left behind, they carried shovels, fuel, rope and insulated sleeping bag covers.

But family members have said the three planned to hide their supplies before scaling an ice wall on the northern side of the mountain. After making the summit, they planned to descend the southern slopes and drive around the mountain to retrieve their supplies.