Events and Studies

19th century
In 1832, the Journal of the Asiatic society of Bengal published trekker B. H. Hodgson's account of the Yeti in northern Nepal. His native guides spotted a tall, bipedal creature covered with long dark hair, which seemed to flee in fear. Hodgson did not see the creature, but concluded it was an orangutan.
An early record of reported footprints appeared in 1889 in L.A. Waddell's Among the Himalayas. Waddell reported his guide's description of a large apelike creature that left the prints, which Waddell concluded were actually made by a bear. Waddell heard stories of bipedal, apelike creatures, but wrote that of the many witnesses he questioned, none "could ever give ... an authentic case. On the most superficial investigation it always resolved into something that somebody had heard of."

Early 20th century
The frequency of reports increased during the early 20th century, when Westerners began making determined attempts to scale the many mountains in the area and occasionally reported seeing odd creatures or strange tracks.
In 1925, N.A. Tombazi, a photographer and member of the Royal Geographical Society, allegedly saw a creature at about 15,000 ft (4572 meter) near Zemu Glacier. Tombazi later wrote that he observed the creature from about 200 or 300 yards, for about a minute. "Unquestionably, the figure in outline was exactly like a human being, walking upright and stopping occasionally to pull at some dwarf rhododendron bushes. It showed up dark against the snow, and as far as I could make out, wore no clothes." About two hours later, Tombazi and his companions descended the mountain, and saw what they assumed to be the creature's prints, described as "similar in shape to those of a man, but only six to seven inches long by four inches wide... The prints were undoubtedly those of a biped."

The Pangboche Scalp

The Pangboche Hand and Yeti "Scalp", 1954

Dr. Biswamoy Biswas examining the Pangboche Yeti scalp during the Daily Mail Snowman Expedition of 1954
The Daily Mail "Snowman Expedition" of 1954, on March 19 printed an article which described expedition teams obtaining hair specimens from a scalp found in Pangboche monastery. The hair was analysed by Professor Frederic Wood Jones, F.R.S, D.Sc., (who died on September 29 1954) and an expert in human and comparative anatomy.
The research consisted of taking microphotographs of the hairs and comparing them with hairs from known animals such as bears and orangutans. Professor Woods-Jones concluded that the hairs of the Pangboche scalp were not actually from a scalp. He contended that some animals do have a ridge of hair extending from the pate to the back, but no animals have a ridge (as in the Pangboche relic) running from the base of the forehead across the pate and ending at the nape of the neck.
The hairs were black to dark brown in colour in dim light, and fox red in sunlight. None of the hairs had been dyed and were probably exceedingly old. During the study, the hairs were bleached, cut into sections and analysed microscopically. Wood-Jones was unable to pinpoint the animal from which the Pangboche hairs were taken. He was, however, convinced that the hairs were not of a bear or anthropoid ape. He suggested that the hairs were not from the head of a coarse-haired hoofed animal, but from its shoulder.

Late 20th century
Western interest in the Yeti peaked dramatically in the 1950s. While attempting to scale Mount Everest in 1951, Eric Shipton took photographs of a number of large prints in the snow, at about 6,000 m (19,685 ft) above sea level. These photos have been subject to intense scrutiny and debate. Some argue they are the best evidence of Yeti's existence, while others contend the prints to be from a mundane creature, and have been distorted by the melting snow.
In 1953, Sir Edmund Hillary and Tenzing Norgay reported seeing large footprints while scaling Mount Everest. But Hillary would later discount Yeti reports as unreliable.
During the Daily Mail Snowman Expedition of 1954, the largest search of its kind, the mountaineering leader John Angelo Jackson, made the first trek from Everest to Kangchenjunga during which he photographed symbolic paintings of the Yeti at Thyangboche Gompa. Jackson tracked and photographed many footprints in the snow, most of which were identifiable. However, there were many large footprints which could not be identified. The flattened footprint-like indentations were attributed to erosion and subsequent widening of the original footprint by wind and particles.
Beginning in 1957, wealthy American oilman Tom Slick funded a few missions to investigate Yeti reports. In 1959, supposed Yeti feces were collected by Slick's expedition; fecal analysis found a parasite which could not be classified. Bernard Heuvelmans wrote, "Since each animal has its own parasites, this indicated that the host animal is equally an unknown animal."
In 1959, actor Jimmy Stewart, while visiting India, reportedly smuggled remains of a supposed Yeti, the so-called Pangboche Hand, by concealing it in his luggage when he flew from India to London.
In 1960, Sir Edmund Hillary mounted an expedition to collect and analyse physical evidence of the Yeti. He sent a Yeti "scalp" from the Khumjung monastery to the West for testing, whose results indicated the scalp to be manufactured from the skin of the serow, a goat-like Himalayan antelope. But some disagreed with this analysis. Myra Shackley said that the "hairs from the scalp look distinctly monkey-like, and that it contains parasitic mites of a species different from that recovered from the serow."
In 1970, British mountaineer Don Whillans claims to have witnessed a creature when scaling Annapurna. While scouting for a campsite, Whillans heard some odd cries which his Sherpa guide attributed to a Yeti's call. That very night, Whillans saw a dark shape moving near his camp. The next day, he observed a few human-like footprints in the snow, and that evening, viewed with binoculars a bipedal, apelike creature for 20 minutes as it apparently searched for food not far from his camp. Nothing was seen again.
In 1984, famed mountaineer David P. Sheppard of Hoboken, NJ, was near the southern Col of Everest and claims to have been followed by a large, furry man over the course of several days. His sherpas, however, say they saw no such thing. He claims to have taken a photograph, but a later study of it proved inconclusive.