Introduction to Geocaching!

What is geocaching?

Some people call geocaching a hi-tech treasure hunt or hi-tech hide-and-seek. Others call it the technological successor to letterboxing. Just about everyone calls it FUN!

Geocaching is a family-friendly adventure in which a hider will hide a geocache (or cache for short) and mark it's latitude and longitude with a GPS receiver (GPSr). The hider will then post those coordinates online with a description and possibly hints. Then seekers will be able to read the description, hints and coordinates. The seeker enters the coordinates into a GPSr and goes to find the cache.

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What is GPS?

GPS is an acronym for Global Positioning System. The full system is made up of at least 24 active satellites and several ground-based monitoring and control stations. Each satellite sends its position down to the Earth where it is picked up by the monitor and control stations as well as any GPSr that is in range. When a GPSr receives signals from at least 3 satellites, it can calculate the postion of the unit to within a few feet. The satellites and ground-based stations are all maintained by the U.S. Air Force. The GPS system became active in 1993.

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How did geocaching get started?

When the GPS system first began, the highest accuracy was reserved for military, aviation and other specific uses. Civilian GPS units would only be accurate to about 300 feet. This was called "Selective Availability". In 1996, President Bill Clinton signed a bill stating that on May 2, 2000, Selective Availability would be turned off.

On May 3, 2000, Dave Ulmer hid a 5-gallon bucket in the woods in Oregon. He posted the coordinates to a USENET newsgroup on the internet to see if anyone could find it. He did this to test the accuracy of the GPS system. Within 3 days, 2 seekers had found the bucket and posted the experience online. It all began right there.

On May 30, 2000, the term "geocaching" was first used to describe this activity. As more and more people began to get involved, Mike Teague began a database of these caches. Later, Jeremy Irish started his own site to keep track of these. His site,, went live on September 25, 2000, with 75 caches. As of April 27th, 2009, there are over 785,000 caches around the world!

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Although there are other sites that catalog their own form of geocaching, the most popular by far is This guide and this site focuses on

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How many caches are there?

As of May 2, 2010:

Caches around the world: 1,055,904

Caches in South Carolina:  4,561

Caches in North Carolina: 16,436

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What is a cache?

A cache is a container that at least contains a log to sign. Popular cache containers include ammo cans, lock-n-lock's, 35mm film canisters, bison tubes, etc. Pretty much any type of weatherproof container will work.

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What are the types of caches?

 Traditional - most common cache type. You get the coordinates for the location of the cache.

 Multi-cache - With this type of cache, you get coordinates that lead you to a location where you get more coordinates. You follow those coordinates to the cache or another stage with more coordinates. 

 Mystery/Puzzle - To find this cache, you typically have to solve a puzzle (crossword, sudoku, etc), break a code or mystery in order to get the coordinates for the actual container.

Event/Mega-event - Event caches are gatherings of cachers. Types of events include instructional events, picnics and meet & greets. Mega-events are larger events that usually bring cachers together from all around. GeoWoodstock is a yearly Mega Event which brings cachers from all around the world together for a weekend of fun and caching.

 CITO - Cache In, Trash Out (CITO) are specific events where geocachers get together to pick up trash. Geocachers try to give back by helping clean up the environment.

 Virtual* ** - Virtual caches have no physical container to find. With a virtual, you go to the specified location and have to provide alternate proof you were there. You could have to provide a photo of yourself at the location or answer a question based on something at the spot.

EarthCache** - EarthCaches are very similar to virtual caches but have an educational element to them. EarthCaches are located at geologically or geographically interesting locations. Seekers are required to answer questions about the location in order to claim the cache. Locations could be mountain tops, canyons, wetlands, the meeting of oceanic currents, etc. EarthCaches go through an additional review process by the Geological Society of America.

WebCam* ** - WebCam caches require that you go to the location of a publicly viewable webcam. You position yourself so you are visable on the camera then have someone with a computer view the webcam and save a screenshot of the image. That is your proof you were at the location.

* This cache type is no longer available for creation. Existing caches of this type are still available to find.

** This cache type does not have a physical container with a log to sign.

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What is in a cache?

At the minimum, caches contain a log so seekers can sign and date the find. Some caches are small so that only a log will fit and seekers will need to provide their own pen. Larger caches can contain trade items, also known as swag. Trade items can be just about anything that will fit in the container. Common items include AA batteries (for your GPSr), Hot Wheels cars, trading cards, trackables such as travel bugs and geocoins (more on that later), individual cacher signature items, stuffed animals, etc. The general rule on trade items is to trade even or trade up. If you see something in a cache you want, please be sure to place something else in. 

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What is NOT in a cache?

There are guidelines to things that should NOT be placed in a cache. The following items are prohibited:

    Adult materials : Remember, this is a family friendly activity and children may be finding the caches.

    Food : it attracts bug and critters that could damage the cache.

    Ammunition, Fireworks, Weapons such as guns, knives, etc

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How and where are they hidden?

Caches are hidden just about anywhere. However, they should NOT be buried or in any way cause damage to the location where they are hidden. They can be hidden under sticks, hanging in trees, magnetically attached to metal such as guardrails, or even underwater. They can be hidden on city streets, the tops of mountains, on islands in the middle or rivers, just about anywhere.

Many city, county and state parks have caches. However, land managers have the final say on if caches are allowed or not. The North Carolina State Parks system and the National Park Service have decided to not allow caching. There are groups that are trying to change that, though.

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Are there rules for geocaching?

Yes. Most rules come into play when you hide your own cache. But knowing the rules will also help when you are seeking out a cache.

Caches should be at least 528 feet (.1 mile) from any other cache or from a stage of another multi-cache.

Caches should not be within 150 feet of any active railroad tracks.

Caches should not be near, on or under structures deemed possible terrorist targets such as government buildings, dams, bridges, etc.

Land manager permission is required.

No "vacation" caches. Caches require occasional maintenance (log full, container damaged, etc). Therefor caches should be placed within range of the cache owner. If you live in South Carolina, you will not be allowed to hide a cache in California.

All caches go through a review process. Each state has at least one volunteer reviewer who checks all caches to make sure they fit the guidelines. However, reviewers do not visit each and every cache location. Much of the rules enforcement comes from cachers themselves.

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So what's the point?

Geocaching means different things to different people. If you ask 10 geocachers why they do it, you will probably get 10 different answers. Many people enjoy the merging of nature and technology. Others enjoy getting a large number of finds. Most people will probably tell you that geocaching has taken them to places they never would have gone if not for geocaching. And for others, the finding the cache is secondary to the journey to the cache.

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How much does it cost?

The site offers two types of accounts: basic and premium. The basic account is free while the premium account is $30 per year. With the free basic account, you can search online for caches, read all the descriptions, hints and logs as well as get the coordinates. With the premium account, you can do more advanced searching through Pocket Queries, maintain bookmark lists of your favorite caches, and get notifications of new caches as soon as they are published.

For GPS receivers, the cost varies. You can get an entry level model for around $80 or so. More advanced models can be well over $500. You just need to find the model that fits with the way you want to use it.

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Sources and for more information, please see the following sites: