Much of the topography of this site was formed by glaciers. Running north and south through western McHenry County to Kane County, Marengo Ridge — a glacial moraine left by the last Ice Age — is three miles wide from east to west, and 200 feet thick. Made of sand, gravel, clay, and boulders, it is the westernmost and oldest of the moraines in our region.
How do end moraines form?
Melting at a glacier margin causes the ice to thin, and ground-up rock debris carried in the base of the ice or dragged along beneath the glacier is deposited. When the ice margin remains in the same place for a relatively long time (tens to hundreds of years), enough debris flows to the glacier's leading edge and piles up to form a large end moraine on the landscape.
What are end moraines made of?
The unsorted mixture of debris deposited by a glacier is called till. Most end moraines in Illinois are thick ridges of till. A ground moraine, the relatively flat, low-lying landscape across which the melting glacier retreated, consists of a thinner layer of till. Sheet like deposits of sand and gravel, called outwash plains, were left behind by melt water streams flowing away from the glacier.
To log this cache, please email me the answer to the following questions:
1. At this location, you are standing on what is known as an end moraine. An end moraine is a moraine that forms at the end of the glacier called the snout. How long ago was this deposited here?
2. What is the most visible ridge to the east and when was it deposited?
3. What is the elevation at this location?
4. Please post a picture of yourself with your GPS along with your log.
McHenry County Conservation District Cache Your Way Across McHenry County GeoSeries
Geocaching is a high-tech “treasure hunting” game played throughout the world by adventure seekers equipped with GPS device. 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 for the next person. Share your experiences through geoaching.com.
To participate in our program and earn a special District geo-coin, follow these simple steps.
- Download a McHenry County Conservation District Cache Your Way Across McHenry County GeoSeries Passport from our website
- Go to geocaching.com and create a login (it’s free for a basic membership!) and find the coordinates/info for the program.
- Start your search and locate a cache using a hand-held GPS unit. Our have official District labels.
- When you find a cache, log your name on the logbook inside. If you are participating in the program, be sure to write the answer to the question in your passport.
- A couple of the caches 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.
- 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 at the location before heading to it! Hours and days open vary depending on site.
Prairieview Education Center
Lost Valley Visitor Center
Brookdale Administrative Offices
If you are unable to make it to a facility when it is open, you may also mail it to:
McHenry County Conservation District
Attn: Geocaching
2112 Behan Road
Crystal Lake, IL 60014
Or e-mail a copy to geocaching@mccdistrict.org
Geocachers
Please join us in playing! All are welcome who observe and obey the rules. Please do not move or vandalize the container. Replace the cache in the same spot in like or better than you found it and when you leave, make sure the cache is completely covered. Please do not remove the informational card from the containers, this is a essential game piece for cachers completing the GeoSeries. The real treasure is just finding the container and sharing your thoughts with everyone who finds it.
District Geocaching Rules
For a complete list of rules, visit our website MCCDistrict.org/Geocache
McHenry County Conservation District Information
Visit our website at MCCDistrict.org or call 815-338-6223 ext 1211 for camping/shelters, 815-479-5779 for educational programs or 815-678-4532 for the Lost Valley Visitor Center
Photo Release
5/20/2021 Photos posted here may be featured on the McHenry County Conservation District's various social media accounts including Facebook, Instagram, and twitter, as well as our website (MCCDistrict.org) and print material such as Landscapes Magazine. By posting photos to this log you agree to allow us to share your work with our followers. Photographers will be acknowledged in any shares or posts of photos, so please include your name in your post if it is different from that of your username.