Two mountain climbers stranded on Mount Dickey in Alaska's Denali National Park and Preserve were rescued Monday evening after triggering a massive slab avalanche on the peak.
The two men -- Saxon Spellman, 27, and Michael Wachs, 24, both from Idaho -- weren't caught in the avalanche but found themselves stranded at 7,500 feet without a safe exit route, National Park Service spokesperson Maureen Gualtieri said.
They had triggered a "significant" slab avalanche that spread to slopes both above and below the climbers, said mountaineering ranger Dan Corn.
Corn described a slab avalanche as one that "looks like a cookie cutter" stamped into a mountain that then slides down the slope.
The two men were spotted by an air taxi pilot, who saw them waving their arms above an SOS they made in the snow on the west shoulder of the peak, Gualtieri reported.
An Park Service helicopter was already en route when the climbers activated the emergency setting of their GPS SPOT device, which alerted the Rescue Coordination Center, Gualtieri said. Pilot Andy Hermansky was able to land a helicopter on a flat section of the peak and evacuate the two men.
Mount Dickey is a technical peak rising 9,545 feet in the Ruth Gorge area of the park. Spellman and Wachs were the only climbers seen climbing the peak on Monday, according to Gualtieri.
Widespread avalanche activity has been observed in the Ruth Glacier and Kahiltna Glacier areas of the park following a storm that brought several feet of snow and windy conditions, Gualtieri said.
Rangers have seen lingering avalanche conditions "on multiple aspects of the peaks and spanning a broad range of elevations," Gualtieri said. "Climbers are advised to exercise caution due to the persistent nature of the avalanche hazard."
Condition reports are available at the Park Service's Denali Dispatches.