NYPaddlerCacher, The A-Team, speakers-corner, and hzoi, thank you for your input! Although I don't have any hides to my credit, I have found a few dozen caches, although none recently. (Going to school full time at my age is a full time job with no time off. ) Your suggestion to contact a local cacher is a good one, but I wasn't planning on covering the ownership part of geocaching. I considered it, but my column was already a bit long and in order to do justice to the process of hiding a cache, there just wasn't going to be enough space. If I ever end up doing a research project on geocaching I will definitely use your suggestions!
The column I have to write is for a Natural Resources Interpretation class. I chose to write about Geocaching because I enjoy it (when I have the time and someone to go with), and I want to promote it to others who may not be familiar with it. I don't know if anyone, other than my instructor and his teaching assistants, will get to see it, but I wanted it to represent geocaching, and geocachers, as accurately as possible to the potential newbie's point of view.
That being said, I changed the original sentence to the following:
"Although the numbers vary according to what source you look at, it is probably safe to say that there are over 1 million caches worldwide which can be found in over 200 counties."