After the Daily Mail Expedition presented its findings the next westerner to go to the Himalayas specifically to look for the yeti was the American oil man Tom Slick in 1957. According to Wikipedia, Slick's interest in cryptozoology was little known until the publication of Tom Slick and the search for the Yeti in 1989 so it is entirely possible that some of Slick's adventures may have been slightly exaggerated with the passage of time (many of the facts only came to light in public over 20 years after his death) but it is known for a fact that Slick did finance a number of yeti expeditions. Slick was not interested in the yeti exclusively, and he also funded and participated in expeditions to look for the Loch Ness monster and closer to home, the Trinity Alps giant salamander in California, and Bigfoot.
It was not until 1959 that Slick's yeti expedition found something of note: supposed yeti scat. Analysis of the scat found an unidentified parasite, which led Bernard Heuvelmans to write:
'Since each animal has its own parasites, this indicated that the host animal is equally an unknown animal.'
However, this was just an example of Heuvelmans getting a little over-excited, as he was prone to do on several occasions in his otherwise distinguished career (for example, see the Minnesota Iceman incident). In reality the presence of an unknown parasite certainly does not indicate that it came from an unknown animal; scientists find previously unknown parasites in all number of known animal species, including man.
The Tom Slick yeti story that everyone knows, though, also took place in 1959: the story of Jimmy Stewart and the yeti's hand. Slick had heard of the existence of a mummified yeti hand in Pangboche monastery, Nepal, on the 1957 expedition and photographs had been taken of the hand by Peter Byrne in 1958. The plan was that the team would take the hand away for testing in the 1959 expedition; however, when the monks refused permission for this Byrne is said to have taken bone samples from the hand while the monks were distracted, and replaced them with human bone fragments. Byrne is then said to have smuggled the bone fragments into India where he met up with the Hollywood actor James Stewart who smuggled them into the United States of America. The analysis conducted on the samples, and a DNA analysis in 1991, concluded that they were 'near human', which sadly does not tell us a lot.
After the 1991 DNA analysis the entire hand was stolen from the monastery. Edmund Hillary visited the monastery in 1960 but concluded the hand was a fake. However, those that believe in the hand's authenticity have said his conclusions were largely based on the “modifications” made by Byrne to cover up for the sample he had taken.
Hillary's expedition to Nepal in 1960 was in part thought to be a cover for an expedition to spy on Chinese military technology and activity but he did take the yeti-hunting part of the expedition seriously and as well as investigating the Pangboche hand, obtained what was alleged to be a yeti scalp from Khumjung monastery in Nepal. The scalp was subjected to scientific testing and it was concluded that, far from being a yeti scalp, the skin had come from the hide of a serow. Myra Shackley, archaeologist and author of Wildmen: Yeti, Sasquatch and the Neanderthal Enigma contested the findings claiming that the hair looks distinctly monkey-like and the parasitic mites found on the scalp were of a different species to those found on the serow. A discrepancy of mites does not necessarily indicate that it is not a serow though because different mites and parasites will feed on dead tissue, long dead tissue like the 'yeti scalp' in particular, than living tissue.