To pick up the rescuer and Slemp, the pilot "then [did] the same thing to go back in."
Slemp was pretty banged up but he was healthy enough to scramble down and get into the helicopter. His leg was splinted and the rescuers checked him out as the helicopter flew back.
The rescue effort was swift and wrapped up in 2.5 hours, by about 7:30 p.m. PT.
Cox said that injuries on Mt. St. Helens are fairly common. "We have injuries on the mountain just about yearly from people trying to climb ... you get people who are 'day hikers' who think it's just a stroll up to the crater rim, but it's still a fairly technical mountain to climb."
As Slemp left the crater in the rescue helicopter, his son and friend left the crater rim to return home in the car they drove in. Slemp appeared to have one more thing on his mind, and he made a request of his rescuers.
"Did you tell those guys that the car keys are in the snowmobile, parked at the top of Mt. St. Helens?" he asked.
Slemp was taken to Yacolt, Wash., for medical care, and transferred to Legacy Emanuel Hospital in Portland, Ore. The hospital did not return calls inquiring about Slemp's condition, but Slemp's brother-in-law Randy Fairley told ABC News that, to his knowledge, Slemp was recovering.