Ansel Vizcaya, 29, from Missoula, Mont., and his climbing partner, Luke Casady, 29, of Stevensville, Mont., climbed Liberty Ridge along the north side of the 14,411-foot peak, where two others have died in recent weeks.

Casady's body was recovered early Friday from the 9,000-foot elevation on Carbon Glacier below Liberty Ridge. Rangers believe an avalanche swept Casady 4,000 feet to his death and might have claimed his partner as well.

Searchers found Vizcaya's backpack near where they found Casady's body.

"At this time, he is presumed dead," Mount Rainier National Park spokeswoman Patti Wold said.

Thunder clouds that moved in after Saturday morning's rescue prevented a helicopter search for Vizcaya, Wold said.

A helicopter scheduled to drop supplies into the backcountry over the next week would be assigned to fly over the area looking for his body, Wold said.

Park also will ask climbers heading up Liberty Ridge to look for any signs of Vizcaya and report back to rangers, Wold said.

Vizcaya was an employee of North Cascades National Park in northern Washington but was climbing on his own time, climbing ranger Mike Gauthier said.

A graduate of The Evergreen State College, he was beginning his third season working summers for the National Park Service as a fire effects monitor, Wold said.

"Ansel was a mountaineer, an amazing connoisseur of music and laughter, and a very fun guy to be around. He has many people who love him and are affected by this incident," the family said in a statement released by Wold.

Meanwhile, a Chinook helicopter flew two stranded climbers off Mount Rainier on Saturday morning, two days after they called for help saying they were unhurt but in over their heads.

Rangers did not rush to rescue Al Hancock, 44, of Fort McMurray, Alberta, and Bruce Penn, 48, of Connecticut, since they said they had food and fuel and weren't in immediate danger.

A Chinook helicopter from the Oregon National Guard dropped a ranger at Thumb Rock, around the 10,670-foot level, on Saturday morning. The ranger strapped the climbers into harnesses and they were flown off the mountain around 10 a.m., Wold said.

Gauthier, the rescue mission's incident commander, planned to interview the men at the Longmire ranger station, Wold said.

Park officials say more than 11,000 people try to climb Mount Rainier annually. About 200 of them try Liberty Ridge, considered one of the most challenging routes on the mountain.

Jon Cahill, 40, of Auburn, died June 3 after falling 200 feet on Liberty Ridge. Peter Cooley, 39, of Cape Elizabeth, Maine, died May 17, two days after he tumbled down a steep icy slope of the ridge and hit his head on a rock spur.

An average of three people a year have died in summit attempts since 1990. Casady's death was the 92nd since 1887, when records were first kept.