Geocache / Letterbox

Geocaching is a high tech “treasure hunting” game played throughout the world by adventure seekers equipped with GPS devices or smart phones.  The general idea is to locate hidden containers called geocaches or simply caches. Once you find it, take a trinket and leave one of your own behind, sign the logbook and share your experiences through

Geocaching on McHenry County Conservation District property - due to the similarity, all rules apply to Letterboxing as well:
  • Follow all District rules and regulations - all geocaches are required to be 12 feet or less from a designated trail.  You may leave the trail for the cache as long as you are within the 12' 
  • Geocaches may not be affixed to any natural or man-made structure with the exception of magnetic caches.  Magnetic caches cannot be placed on any electrical boxes, pipes or other mechanical structures.
  • Light pole caches ("lpc") are not allowed
  • Certain areas may be closed to geocaching for a variety of reasons
  • Permission must be obtained prior to placing a cache
Complete list of geocaching /letterboxing rules.

Cache Your Way 2021

Each year the District puts together a Cache Your Way Challenge.  August 1 -November 30
The 2021 program's theme will be in celebration of the District's 50th Anniversary.  Complete the sheet and earn the special coin by completing this program.  There are a limited number of coins—first-come, first-served; one coin per household.  **For the 50th Anniversary we will have 200 coins available!!!**
Download Answer Sheet
50th logo no background
Find us on Facebook Cache Your Way Across McHenry County Group

Cache Your Way Across McHenry County Ongoing GeoSeries
The District also maintains an ongoing GeoSeries, Cache Your Way Across McHenry County, highlighting the BEST spots throughout the McHenry County Conservation District.  A GeoCoin is available for the completion of this program as well. To participate in our program and earn a special District geo-coin, follow these simple steps:

1.) Download a McHenry Conservation District Cache Your Way Across McHenry County  GeoSeries Passport
***Passport updated 6/1/2020 due to one cache temp unavailable
2.) Go to and create a login – it’s free for basic membership!
3.) Start your search and locate a cache using a hand-held GPS unit or a GPS app on your smartphone. Our containers are clear plastic containers and will have official District labels and info cards.
4.) When you find a cache, log your name on the logbook inside. Write the answer to the question in your passport. (Information and your question is located on the cache’s page on Exceptions are the Earthcaches: there are no log books or containers at Earthcaches – and the two smaller-sized caches.
***If you have already found the 4 pre-existing Earthcaches you do not need to find them again! If you remember the answers, use those. If you do not, simply put the date and your geocaching ID down for staff to check the logs to see your recorded visit.***
5.) Some of the caches may have travel bugs. Please move these bugs along and do not keep them! You will get your own to keep when you finish the program.
6.) Complete all the caches and bring your passport to one of our facilities to claim a coin. Be sure to check each facility’s hours before heading out. Hours and days open vary depending on the site.***See Special 2020 Note for claiming this coin as well

Prairieview Education Center | Lost Valley Visitor Center | Brookdale Administrative Offices

OR mail it to:
McHenry County Conservation District
Attn: GeoSeries
18410 US Highway 14
Woodstock, IL 60098

OR e-mail a copy to

***Note on site closures or temporarily disabled caches***
If you are traveling from out of town and a cache is temporarily disabled either due to a site closure or some kind of issue with the cache, on the passport record disabled and the date. You will still be able to claim a coin!