In 1953, Sir Edmund Hillary and Tenzing Norgay climbed Everest, and reported seeing large tracks. In 1954, the Daily Mail (UK) funded a sixteen-week “Snowman Expedition” to Everest to look for clues. The mid-fifties were when the search for the Abominable Snowman a/k/a Bigfoot a/k/a Sasquatch a/k/a Yeti cranked up to a fever pitch.
Enough Yeti expeditions were launched that the Nepalese and U.S. Governments issued a set of regulations for Bigfoot hunters and researchers. “Regulations Governing Mountain Climbing Expeditions in Nepal—Relating to Yeti,” was issued from the American Embassy in Kathmandu on November 30, 1959.
From The U.S. National Archives:
click to enlarge