Two climbers, battling hypothermia, were in a snow cave Thursday on the "Football Field" waiting to be rescued/NPS graphic

Two climbers, exhausted and battling hypothermia, remained stuck Thursday high on Denali where they were awaiting rescue in a "crude snow cave." 

Climbing rangers from Denali National Park, ready to make a rescue push, were looking for a break in the weather at a high camp at 17,200 feet on the 20,310-foot mountain, roughly 2,400 feet below the stranded climbers.

The two men, age 36 and 47, from Malaysia, had summited North America's tallest mountain earlier this week with a third climber, age 48 and also from Malaysia, according to the National Park Service. It's believed that batteries in their InReach communication device might have died sometime Wednesday night, when five brief messages came through in rapid succession from the two men, confirming their location and requesting help. The last message indicated their InReach battery was almost completely depleted, a park release said.

Clouds and high winds on the upper mountain prevented ground teams from moving any higher than the 17,200-foot high camp on Wednesday. On Thursday morning, a ground crew of park rangers and mountaineering volunteers at the high camp were on standby to move higher on the mountain once winds abate. The park’s high altitude helicopter pilot was likewise on standby until conditions were safe to fly.

The trio's ordeal began around 1 a.m. Tuesday local time when they sent an SOS message from their InReach satellite communication device, saying they had summited the mountain but were hypothermic and unable to descend. According to a park release, "rangers maintained two-way communications with the team until approximately 3:30 a.m., when the team texted that they planned to descend to the Football Field," a flat spot on the mountain at an elevation of 19,600 feet. Rangers did not hear back from the team after that transmission, nor did the location of the device change. 

Cloudy conditions Tuesday morning prevented the park's high-altitude helicopter from reaching the mountain from Talkeetna, resulting in rangers contacting the Alaska Rescue Coordination Center (RCC) for assistance. At 10 a.m. Tuesday the Alaska Air National Guard launched an HC-130J Combat King II from Joint Base Elmendorf-Richardson, Alaska, to attempt to locate the climbing team.  

The Alaska Air National Guard Pararescuemen on board the HC-130 spotted two of the three climbers between 19,000 and 20,000 feet shortly before noon Tuesday, the park release said. The third climber was located by a climbing guide near Zebra Rocks at 18,600 feet. Although winds were relatively calm on Tuesday, several stagnant cloud layers prevented the park’s high-altitude helicopter from reaching the climbers safely, it added.

At 5 p.m. Tuesday the park helicopter pilot and a mountaineering ranger took advantage of a clearing trend and made a second flight attempt of the day to the upper mountain. Although Denali’s summit was in clouds, the helicopter was able to reach the 14,200-foot camp. 

Around 9 p.m., the park helicopter pilot and ranger attendant made their third attempt of the day to reach the distressed climbers on the upper mountain. "By that point, one of the three climbers had made their way down to the 17,200-foot high camp with severe frostbite and hypothermia. A guided party initially assisted the patient until transferring care to an NPS ground team who had ascended to high camp from 14,200-feet to support the rescue effort," the park release said.

At 10:15 pm, the park helicopter pilot flew to the 17,200-foot camp, picked up the ailing patient, then flew to the 7,200-foot Kahiltna Basecamp to refuel. As clouds began to build up again on the upper mountain, the park helicopter and rescue crew returned to Talkeetna with the one critical patient and transferred care to a LifeMed helicopter.

Meanwhile, an experienced expedition guide on the upper mountain had diverted significant time to assist and provide care to the two non-ambulatory climbers at the Football Field, the park release said. However, when the clouds moved back in late Tuesday night, the guide was forced to return to the 17,200-foot high camp for his own safety and for the safety of his team. 

Memorial Day weekend is the start of the busiest two weeks of the Denali mountaineering season. As of Wednesday morning, there were 506 climbers attempting climbs on Denali. So far this season, an additional 117 climbers have come and gone, 17 of whom reached the mountain’s summit, equating to a 15 percent summit rate. One climber died earlier this month in a fall while trying to reach the summit of Denali via the West Buttress route.