Yeti Tracks at the Kongmaa La Camp, Arun Valley Wildlife Expedition (1972)

The Arun Valley Wildlife Expedition set out to survey the country between Everest and Kanchenjunga, on behalf of the Thailand Association for the Conservation of Wildlife. Its chief scientist was the zoologist Edward W. "Ted" Cronin Jr. Its mammalogist was Jeffrey A. McNeely. The physician was Dr Howard Emery.

In December 1972 the party pitched two tents in the snow on a ridge running off the Kongmaa La, in the upper Arun and Barun Khola country. The altitude was about 12,000 feet.

No sounds were reported. Nobody saw the animal. Shortly before dawn on 18 December, Emery climbed out of the tent he shared with Cronin. He called excitedly. "There, beside the trail we had made for our tents, was a new set of footprints," Cronin wrote. "The Sherpas identified the tracks without question as yeti footprints."

The prints measured about nine inches by four and three quarters. Each showed a short, broad, opposable big toe, four other toes set unevenly and a wide, rounded heel. Cronin and Emery photographed ten to fifteen clear prints before the sun could soften them. The stride was surprisingly short. Often less than one foot. "It appeared that the creature had used a slow, cautious walk," Cronin wrote.

By the direction of the toes, Cronin worked out that the animal had come up the north slope, leaving large punch holes in deep snow. He descended several hundred yards. His verdict: "the creature must have been exceptionally strong to ascend this slope." It had walked along the ridge between the two tents, then down the south slope. From higher up, the scientists watched its trail cross back and forth several times. McNeely came up afterwards with plaster of Paris and made casts.

In 1973 McNeely, Cronin and Emery reported the find in the journal Oryx. Their tent, they wrote, "was visited by an animal which left tracks that are not referable to any known animal." Cronin retold the story in The Atlantic in November 1975 and in his 1979 book The Arun. He compared the prints with those photographed by Eric Shipton, "differing only in being smaller, with a shorter hallux, and perhaps indicating an immature or female yeti."

The casts did not survive. In late 1975 the British zoologist Andrew Laurie tried to take them through Kathmandu airport to McNeely in Bangkok. Asked what they were, he answered "yeti footprints." Customs confiscated them as "national treasures." A later search of government stores failed to find them.

George Schaller, the gorilla field biologist, saw in the large opposable toe "a close resemblance to those of the mountain gorilla." Jeff Meldrum discussed the prints in Sasquatch: Legend Meets Science. Darren Naish noted that they differ markedly from the Shipton photograph, with a narrow heel and a much smaller big toe.

Daniel C. Taylor found his own trail in the Barun in 1983. He traced it to the Asiatic black bear, whose hind foot can land over the print of its front foot and leave a human looking track. He later reproduced such prints with a tranquilised zoo bear in Kathmandu. Taylor says his letters to Cronin and McNeely went unanswered. No one has alleged a hoax. The casts are gone. The photographs remain, among the very few yeti tracks ever recorded by professional biologists on a scientific survey.