Roche-A-Cri: Grotesque Towers
The park road is a short loop and there is
parking available at several locations. Winter Parking can be found
at: N43 59.777 W89 49.039. Please use due caution if planning a
winter visit as your hike will be longer, ski trails must be
avoided and the steps and trails may be icy. The accent to the
observation deck in winter is not recommended. The foot bridge from
the winter parking area may be subject to high water. Dogs are not
allowed up to the observation deck.
To log this cache you will need to take and upload a photo
and email me the answers to some questions.
This area of Wisconsin is dotted with tall rock formations which
resemble ruined castles. The steep cliffs with their sharp angles
seem out of place here resembling more closely formations found
much further west on the Great Plains of the Dakotas and Montana.
Here sandstone crags jut out from an unusually flat plain. How did
these formations come to be?
Hundreds of millions of years ago an ancient sea left
sedimentation deposits here and all but the most resistant of these
layers were eventually worn away by wind, water and ice. What you
see here today are the last remnants of those resistant layers.
The bluff which stands before you is one of a few isolated and
rocky hills which rise from the surrounding plains. This formation
is what is correctly known as a mesa (Spanish for "table") as it is
a large formation. Smaller formations are known as buttes and
pinnacles. Located in the "Driftless" (not glaciated) area of
Wisconsin, these mesas, buttes and pinnacles escaped the land
scouring activity of nearby glaciers. It's likely that hundreds or
even thousands of similar formations (which were located outside
the Driftless area) were worn away during the last ice age.
Because the capping material on these bluffs is cemented better
than the under-laying material, erosion by wind and water wears
away the soft sides of these formations until the weight of the
overhanging cap causes it to fall. Frost is also major cause of
erosion and tends to break the formations along joints keeping the
tabletop appearance of many bluffs intact. This formation will
continue to decrease in size until it eventually blends in with the
plain on which it sits; this erosion accelerates once the resistant
capping material has been lost.
Some of these formations stood as islands in Glacial Lake
Wisconsin, while others were submerged. For several hundred years
the lake's waves eroded the edges of the bluffs, giving them their
distinctive steep sides. When an ice dam broke some 15,000 years
ago the lake was released and the formations you see today were
reveled.
Logging Requirements: In order to log this as a find you must
meet the below requirements:
1. Take (and upload with your found it log) a photo of your team
WITH your GPS (or your GPS alone) at a recognizable area within the
park. Please do not photograph the sign at the posted
coordinates.
2. Email me the answers to A, B, C and
D OR A, B, E and F:
* Answers for A & B are at the posted coordinates. Answers for
C,
D,
E &
F can be found at the base of the stairs or at the top of
the bluff.
From the "Outliers of Glacial Wisconsin" sign:
A. Roche a Cri and other rock outcroppings had their beginnings how
many years ago?
B. The sediment here settled into extensive beds of sandstone and
_________?
If you are able to climb the stairs to the top of the
bluff:
C. Using your GPS, what is the altitude at the top observation
deck?
D. How many informational signs are located here?
If you are not able to climb the 303 stairs to the top of the
bluff:
E. Based on the sign at the base of the stairs, what kind of a
climb is this?
F. What is not allowed on the stairs?
Sources & Permission:
http://www.wisconline.com/wisconsin/geoprovinces/centralplain.html
http://www.nps.gov/history/history/online_books/science/2/chap8.htm
Permission for this listing has been granted by Thomas A. Meyer,
Conservation Biologist, State Natural Areas Program, Bureau of
Endangered Resources, Wisconsin Department of Natural Resources.
Prior to placing a geocache on state land one must submit the DNR
Geocache Notification Form to the appropriate land manager:
http://www.dnr.state.wi.us/org/land/parks/other/pdfs/form2500-118.pdf
Special thanks to geocache team sandlanders for their help with
this listing.