This is fantastic. Everyone knows that the service exists, but I had no idea how it got started. Hooray for public servants with senses of humour (and ice in their veins).
It all started in 1955 with a misprint in a Colorado newspaper and a call to Col. Harry Shoup’s secret military hotline. Shoup played along with the tiny voice who called, and a tradition was born.
Source: NORAD’s Santa Tracker Began With A Typo And A Good Sport