Geocaching – High Tech Treasure Hunting

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Geocaching takes treasure hunting one step further by using GPS units to located hidden treasures. The name of the game is a combination of “Geo” from geography and “Caching” from the action of hiding the cache (or treasure). The term cache is commonly used among hikers and campers to refer to a hidden supply of food or other provisions. Geocaching is also referred to as GPS Stash Hunt. Anyone armed with a GPS unit and a sense of adventure can play.

History of Geocaching

According to, the game of Geocaching apparently was birthed May 3rd, 2000when Dave Ulmer hid a cache and posted the coordinates on the sci.geo.satellite-nav newsgroup. The games was made possible by the end of Selective Availability which had previously thrown GPS coordinates off by up to 100 meters.

Playing the geocache game

This game centralizes on three simple rules:

    1. Find the cache and claim the prize.
    2. Leave another cache prize behind
    3. Record the discovery in the log book.

Where are the geocaches?

Caches can be placed anywhere in the world. Successful caches are placed in locations challenging enough for the seeker but not impossible to find. Most importantly, places accessible both physically and legally to treasure seekers should be sought.

Creating a geocache

Cache locations are logged at the Geocache site. Participants can fill out an online form providing information such as coordinates (WGS84 format)and difficulty of finding the cache. Registration is required but free. There are over 2,000 registered users and the webmaster, Jeremy Irish estimated about 2-3 times that are participating in the game.

What’s in the geocache?

The actual items placed in the cache is entirely up to the person responsible for hiding the cache. Items can range from something as simple as a log book that each person that finds the cache can contribute to. More generous caches could contain books, CDs or other desirable items. The items left in the cache are completely up to each person, although common sense and decency dictate that perishable, dangerous of offensive items be omitted. Items are placed in a water-tight container along with a log book and pen to creating a running record of cache-finders.

Prince William Forest Park Cache (source: Jay Chamberlain)

Where can I find a geocache near me? has a clickable map on its home page that lists known cache by distance from the point on the map you click. Clicking on a location of the map will bring up a table showing the nearest caches ordered by distance. Also listed are contact emails, supplemental notes and an “X marks the spot” link to MapBlast. allows you to search for caches by zipcode or state within the United States and by country worldwide.Other cache sites

Matt Stum’s Geocacheaches near Brier Hill

Geocaching Resources
Find Geocaching sites, join the discussion forum and create your own account to be notified when caches are created near your area

GPS Stash Hunting in Belgium
Geocaching site in Belgium. Map of caching sites worldwide.

GPS Stash Mailing List
Yahoo Group mailing list devoted to Geocaching.

Introduction to Recreational Geocaching
June 6, 2000 article by Dave Ulmer posted at the Spatial News site on Geocaching.

Matt Stum’s Geocaches near Brier Hill
Personal Geocaching site with clues to finding caches in Michigan. Distance calculator tool helps you determine how far you are from various listed caches.

Also known as The “Other” Geocaching Site, is an alternative site focusing on quality caches and friendly competition. Getting sponsored is easy, so come on in, the caching is fine.

Suggest a resource by emailing

Other Coordinate Games

The Degree Confluence Project
The object of this game is to visit the intersections of each whole latitude and longitude (e.g. 118° N, 36° E) and take pictures of the site. Photos of visited confluences are posted to the site. According to the site, over 11,650 confluences are still left to be photographed. Field notes on the trials and tribulations of reaching some of the intersections are also logged, make this a great geographical site.

Letterboxing is a similar concept to the GPS Cache game in that waterproofed treasures are hidden in which clues for its location are provided in the form of coordinates and compass bearings. This game is mostly played in England and in some locations in the United States.

 Article first published Jan 23, 2001 and updated on March 2, 2011.

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