Three climbers who fell from a ledge while ascending Mount Hood are huddled in their sleeping bags with a Labrador retriever to keep warm, according to an official with the rescue team.
Rescuers should reach the climbers soon, and evacuation efforts will begin at first light, said Russell Gubele, command officer for Mountain Wave Search and Rescue.
Rescuers have been communicating with the stranded climbers by cell phone.
Crews are working against "terrible" weather conditions, Gubele said, and a high avalanche hazard that will get worse later in the afternoon.
The three stranded climbers fell over a ledge Sunday. They were climbing with five others, who have all been taken down the mountain to a lodge, according to rescue officials.
The accident occurred in whiteout conditions at an altitude of more than 8,300 feet in the area of Illumination Saddle, said the Clackamas County Sheriff's Office, which got news of the missing climbers shortly before noon (3 p.m. ET).
Two of the climbers who fell off the ledge suffered minor injuries, but all others were unharmed, according to Gubele.
"They are doing fine. Both of them had some minor head injuries and they're cold, but they are OK, and they're all conscious, and we talk to them, and they're -- under the circumstances, they're doing remarkably well," he told CNN's "American Morning."
The climbing teams were well-equipped with adequate clothing and climbing equipment and mountain locator units, electronic devices intended to enable rescuers to pinpoint a climber's location, according to Jim Strovink, a spokesman for the sheriff's office.
The five climbers who called about their three missing colleagues were found late Sunday afternoon in snow caves and rescuers began the process of getting them down the mountain, Gubele said.
A short time after the first group of five was reached, the searchers pinpointed the location of the others, Gubele said.
In addition to the sheriff's office, American Medical Response, Portland Mountain Rescue and Mountain Wave Communication Specialists were involved in the search.
Sunday's incident marked at least the second climbing expedition to require rescue in the past few months on Mount Hood.
After a long search in December, rescuers gave up efforts to save a party of three climbers who went missing on the mountain. Only one of the climbers was found -- in the snow cave where he had sought shelter and apparently died.
More than 35 climbers have died on Mount Hood in the past 25 years, according to The Associated Press.