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Lime Kilns: High Cliff State Park
Park information and human history
Between 1,000 and 1,500 years ago, the nomadic Siouan Indians built effigy mounds here. You can view the four panther-shaped mounds, two buffalo-shaped mounds, conical mounds, and a linear mound just a short walk or drive up the hill. In the 1800s this area was noted for its amazing views of Lake Winnebago and became a frequently visited site. A limestone quarry operated here for over 100 years until 1956 when the state of Wisconsin bought the land. In 1957 High Cliff was opened as a state park.
Vehicle admission stickers are required to enter the park; stickers are available at the park office or use self-registration pay station when the office is closed. The park is open for day use from 6 a.m. to 11 p.m. A park map can be found HERE:
Brief History of the Kilns:
While mining took place here as early as the 1850s, the Western Lime and Cement Company operated a limestone quarry here from 1895 to 1956. The Kilns you see before you were built to extract the lime from the stone. At its peak, as many as 40 people worked at the operation from processing the stone to making barrels to transport it. Many of these workers were recent immigrants from Hungary who lived in one of the 16 worker homes in what had become a small "company town" complete with a telegraph, store, church and tavern. The store still stands and now serves as a museum and interpretive center.
The firing process
Simplified, a lime kiln is an oven used to produce quicklime by the "calcination" of limestone. Limestone is made up mainly of three components: calcium, carbon and oxygen. When limestone is heated the carbon escapes as carbon dioxide, leaving lime. This reaction takes place at 750°F, but a temperature of 1300°F to 2,000°F is usually used to make the reaction proceed more quickly. The process of lime burning was carried out by a kilnsman who was experienced in the reduction of limestone. An experienced kilnsman was required to monitor many variables in order to reduce the amount of "dead burnt" lime which was not useful as an end product. The heating and cooling process took several days.
These kilns were "draw" kilns. Draw kilns operate under the principal of gravity. Limestone is fed into the top of the kiln and the cooked stone is removed from the bed of the kiln. Fireplaces were located at the sides of the kiln where fuel was burnt to cook the limestone. One advantage of the draw kiln was that it could be operated on a continual basis. Even though this type of lime kiln was more effective than past versions, it was still extremely inefficient and the lumber needed to fire it could easily necessitate the clearing of large tracts of woodland. Fuel for these three kilns changed from lumber to coal as hardwoods became increasingly scarce in the area.
After the lime was fired it was cooled in cooling sheds and slaked. Slaking involves adding moisture to the lime; this occurred in a number of possible ways from sprinkling water on the lime to letting it sit and absorb water from the atmosphere. The correct mix is approximately one part lime to one part water. Other additives were combined with the lime to create various products.
The end days
In the early settlement days the lack of a good system of roads necessitated the production of lime wherever the raw materials were easily mined. As transportation methods improved during the 1900s commercial lime production began to spread throughout the state wherever limestone was plentiful. Competition, hardwood shortages, increased transportation costs, and the growing use of Portland cement, made small-scale kilns became increasingly unprofitable and most gradually ceased production by the early to mid 1900s. The final nail in the coffin for many kilns was the beginning of the Great Depression which saw a near standstill in the construction industry.
The Niagara Escarpment Rocks!
The limestone (calcium carbonate) cliffs you see here are a part of the Niagara Escarpment* which continues northeasterly to the Door County peninsula and on to Niagara Falls. These cliffs were formed by the settling and hardening of a limy ooze at the bottom of the shallow Silurian Sea which covered much of Wisconsin around 400 million years ago. This limy ooze was made up of shell and shell fragments consisting of corals, brachiopods, crinoids and other types of early life. Many marine organisms extract calcium carbonate from the seawater to make shells or bones and when these organisms die their shells and bones accumulate on the seafloor. Over millions of years these sediments harden into what we see today as limestone. Calcium carbonate is found naturally as a component of aragonite, calcite, chalk, marble and travertine.
*The Niagara Escarpment shown above in red is the edge of a thick series of dolomite (sedimentary stone) layers formed during the Silurian age. The rock is very resistant to erosion and stands up in relief as a prominent line of bluffs. This steep bluff owes its prominence to both the resistance of the Silurian dolomite layers and the relative softness of the Ordovician and Devonian era rocks on either side.
Uses of Lime / Calcium Carbonate
· As a filler in plastics.
· As an extender in paints.
· As an ingredient of cement.
· To treat animal hides and leather.
· In swimming pools as a pH corrector.
· In agriculture to improve acidic soils.
· In forensic science to reveal fingerprints.
· As a major component of blackboard chalk.
· In adhesives, sealants, and decorating fillers.
· In water and sewage treatment to reduce acidity.
· As a building material in the form of marble or limestone aggregate.
· Medically as a calcium supplement, an antacid or as a base material for pill tablets.
· When cured, to create firebrick which was used to line furnaces and build fire-resistant structures.
*** KIDS CORNER ***
A long time ago the cliffs you see here at High Cliff State Park were under a shallow sea. In this sea lived trillions of tiny snails and other shelled critters. When these critters died their shells and bones piled up on the bottom of the sea. Pressure from other shells, sand and water squashed them together to form a sedimentary rock known as limestone.
DID YOU KNOW?
Shells are made of calcium just like your teeth!
When limestone is squished really hard it can become marble.
(Your log may be deleted if you do not follow these logging requirements)
E-MAIL ME (Do NOT post in your log)
#1 ESTIMATE: How high are each of the three kilns?
#2 Where was the poor quality rock sent to for processing?
#3 Name the place where the Quick-lime was barreled and bagged.
POST WITH YOUR FOUND IT LOG
#4 Upload a photo taken at a recognizable part of the site and include your GPS in the picture.
The Geocache Notification Form has been submitted to Jason Wiese, Park Manager. Geocaches placed on Wisconsin Department of Natural Resouce 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: http://www.wi-geocaching.com/modules.php?name=Wiki&pagename=Hiding%20A%20Cache