BuzzFeed, the following is a 1959 dispatch from the U.S. government on what to do if you're Yeti hunting in Nepal.
According to the rules from the American embassy, an intrepid Yeti tracker had to pony up to the Nepalese government for a permit; they weren't allowed to kill or shoot at the creature, unless in self defense; all evidence had to be surrendered to the government of Nepal; and all publicity must be submitted to that government before it is published.
Of course, this isn't the first time the U.S. has gotten caught up with the Bigfoot-like cryptid. Back in 1893, Teddy Roosevelt wrote of an encounter with a sasquatch. Also remember that this was a peak season for Bigfoot; in 1951a famous pair of supposed Yeti tracks by famous British mountaineer Eric Shipton. And in 1958, the famous Bluff Creek Bigfoot sightings gained popularity (and were investigated by Yeti believer Tom Slick).