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Spruce Lake Bog: A Hole, Some Plants and Fuel?

A cache by Lostby7 adopted by Lone_Gunman Send Message to Owner Message this owner
Hidden : 8/23/2007
In Wisconsin, United States
1.5 out of 5
1.5 out of 5

Size: Size: not chosen (not chosen)

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Geocache Description:

Spruce Lake Bog: A Hole, Some Plants and Fuel?

The Spruce Lake bog is a 35 acre lake which is managed by the DNR. In 1968 it was designated a Wisconsin State Natural Area and in 1973 it was designated as a National Landmark by the National Park Service, U.S. Department of the interior.

As this is an EarthCache there is NO container. To claim this as a find you will need to complete the tasks outlined below. Failure to complete the tasks may result in the deletion of your log without notice. Visitors MUST stay on the boardwalk trail due to the fragile nature of the bog plants, the presence of poison sumac, and the unstable bog surface.

Lake Cavity Formation


Spruce Lake Bog is a classic example of a kettle hole peat bog. It was formed by a melting block of ice at the end of the last Wisconsin Ice Age approximately 13,000 years ago. As glaciers advanced and retreated, some of the ice blocks were trapped in one spot or were more difficult to melt than other ice flows in the same area. As the free moving glaciers continued to flow they deposited sediments (also known as outwash) around and sometimes on top of these isolated ice blocks. As the ice blocks melted, they left behind depressions in the ground. Many of these depressions filled with snow melt and rainwater producing kettle lakes.

The Bog

Aerial photo

As there are no tributaries in the Spruce Lake bog, moisture is provided entirely by precipitation. Excess rainfall overflows out of the bog, taking with it dissolved tannins polyphenols (astringent, bitter-tasting chemicals) from the plant matter; this is what gives the bog water its distinctive tan color. This lack of active water movement also contributes to a shortage of oxygenation in the water.The high acidity of bogs, in part due to the lack of water flow and the presence of sphagnum moss, reduces the amount of nutrients and even water available for other plants, thus making the environment inhospitable to many forms of plant life. However, even in this harsh environment many plants have been able to adapt and thrive. In fact, the sphagnum moss and other plants such as cotton grass, three-fruited sedge, royal fern, round-leaved sundew, moccasin flower and wintergreen have filled the edges of the bog and produced a floating mat. Insectivorous plants such as pitcher plants and sundews are also common here and require little in the way of nutrients from the water as they have adapted to eating insects. All of these plants and even the animals and insects that die here go on to form a layer of peat.

Peat & Coal


Peat Coal

Peat is mainly an accumulation of partially decayed vegetative (and to some extent animal) matter that is inhibited from decaying fully by acidic conditions, the principal component of which is normally sphagnum moss which is found in abundance here. The growth of peat layers and degree of decomposition (or humification) of materials depends mainly on its composition and on the degree of waterlogging. Peat formed in very wet conditions will grow considerably faster, and be less decomposed, than peat found in drier places.Under the right conditions, peat is the earliest stage in the formation of coal, and even if peat does not transform into coal, it is still highly useful as a source of fire, and fertilizer.

Geologic Importance

Kettles like the one that created the Spruce Lake Bog are important as they shape the landscape we see and also because their formation provides an oasis of distinct plant life that could not normally exist in such regions. The life that forms in these isolated pockets, under the right conditions, can transform into one of man's most important resources, coal.

To claim this EarthCache You MUST complete #1 AND #2 below.

1.) Take a picture of yourself in front of the Spruce Lake Bog sign (optional).


PART I: What is the water PH at the given coordinates? ---} Bring a PH test kit with you.

You will not have to leave the boardwalk.


PART II: How far does the bog mat extend from it's outer edge to the given coords?

Measure the distance from the beginning of the boardwalk to the given wp.

The Geocache Notification Form has been submitted to Thomas A. Meyer Conservation Biologist, State Natural Areas Program. Geocaches placed on Wisconsin Department of Natural Resource managed lands require permission by means of a notification form. Please print out a paper copy of the notification form, fill in all required information, then submit it to the land manager. The DNR Notification form and land manager information can be obtained at:


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Last Updated: on 8/26/2017 7:32:25 AM Pacific Daylight Time (2:32 PM GMT)
Rendered From:Unknown
Coordinates are in the WGS84 datum

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