A little history ...
In 2003 at a GSA conference, a GSA members suggested that the Society become involved in geocaching. A meeting was then held with Geocaching.com along with some land manager partners, such as the US National Park Service to consider a program that would meet land manager issues as well as develop a way to teach the geocaching community something about Earth science. Based on those discussions, a set of basic guidelines were developed which form the core of the current EarthCache publishing guidelines.
The first EarthCache ("EarthCache I" [GCHFT2])was placed by user "geoaware" on 10 Jan. 2004 on a headland in New South Wales, Australia.Within the first year, more than 500 EarthCaches were published, and the there are now well over 20,500 sites in more than 167 countries (as of 1 Mar. 2016).Since the program started, more than 6.3 million people have logged that they have visited EarthCache sites, and the number is growing exponentially.