One rescuer reached the floor of the volcano's crater, but had to abandon efforts to find the 50-year-old man because strong downdrafts were dislodging rocks, Skamania County undersheriff David Cox said. The rescue will pick up again Tuesday morning, he said.
“There are always overhanging cornices of snow this time of year, and unless you look carefully, you may not notice that there is nothing but air beneath you,” said Rocky Henderson of Portland Mountain Rescue in Oregon, who has climbed to the rim several times.
Rescue efforts began when an emergency cell phone call was received early Monday afternoon, sheriff's officials said.
The caller told dispatchers that the climber was approximately 5 feet (1.5 meters) from the crater's edge when a snow cornice collapsed.
The man had a climbing partner who did not fall, Cox said.
He did not provide names of either person.
A helicopter that does contract work for the US Geological Survey spotted the fallen climber on a steep slope near the bottom of the crater but was unable to pick him up because of high winds and whiteout conditions, Cox said.
A US Coast Guard helicopter also had to abort its effort to find the man because of the winds.
The climber was heard blowing an emergency whistle Monday afternoon, and authorities last heard from him just before darkness fell. Cox said the man's condition was unknown.
Mount St. Helens blew its top with devastating force on May 18, 1980, leveling 230 square miles (595 square kilometers) of forest.
The climb to its crater provides outstanding views of the lava dome, blast area and surrounding volcanic peaks, according to the US Forest Service. Most climbers complete the round trip in 7 to 12 hours, but the service's Web site warns people to stay back from the crater's rim because of its instability.
