"They did summit and they got into trouble on the way down," said coordinator Ted Alexander. "What led to the fall, I cannot tell you now."
Gil Weiss, 29, and Ben Horne, 32, fell an estimated 300 meters (nearly 1,000 feet) off a ridge after reaching the west summit of Palcaraju in the Cordillera Blanca range in mid-July, he said.
"Unfortunately, they died whenever they fell because they had been there long in the snow," he said from the nearby town of Huaraz, where he runs a guide business.
He said a private plane had helped the three-person search team piece together what might have happened. He said he would have a better idea of how the climbers died after examining photos taken by rescuers on-site.
Both Weiss, of Queens, N.Y., and Horne, of Annandale, Virginia, were experienced climbers. Weiss was a repeat visitor to the Cordillera Blanca while this trip was Horne's first.
Both belong to the pullharder.org climbers' collective and Horne wrote about the first, six-day leg of their trip on its blog, saying they had been buffeted by hurricane-force winds when the two reached the top of the 20,216-foot (6,162-meter) Ranrapalca.
After a rest in Huaraz, the two set out again on July 11 for an excursion of seven to 10 days. Their families contacted Alexander after 13 days passed with no word from them.
Weiss's sister, Galit, said the two were not carrying a satellite phone.
Alexander said it should not be too difficult to remove the bodies and hoped they could be out on Sunday.
"We'll use manpower to get them down and try to put them on a horse as soon as possible," he said.
Horne was a graduate student in economics at the University of California, San Diego. Weiss was founder of a business in Boulder, Colorado, called Beyond Adventure Productions that specialized in organizing and photographing events in remote and spectacular locations.
The Cordillera Blanca climbing season runs from June to September and the deaths of Weiss and Horne bring to eight the number of mountaineers who have lost their lives in the range so far this year.
At least 40 have been evacuated due to medical problems, mostly altitude sickness and hypothermia, said Maj. Marco Carrera, commander of Peru's police high-mountain rescue team, which was aiding in the recovery of the climbers' bodies.
Many of the roughly 8,000 foreigners who Carrera said climb the Cordillera Blanca annually do so without hiring local guides, whose absence can make the trips more perilous as snow and ice conditions can quickly change.
On the pullharder.org blog, Weiss posted a comment on July 10 that demonstrated his acute awareness of the potential dangers of his passion for climbing. He was contemplating the death of his friend Michael Ybarra, who had been solo climbing in California's high Sierras.
"I sit here in a coffee shop in Huaraz, Peru, planning another foray into the Cordillera Blanca, where the sense that one's life is in the hands of the mountains can be as blinding as the endless white glaciers, and a thirst for glory can darken our better judgment more than the blackness of night."