This EarthCache highlights a unique but misunderstood geological
feature within the Hocking Hills region. This EarthCache was
developed under special permit from the Ohio Department of Natural
Resources, Division of Parks and Recreation with special assistance
from Chris Grupenhof. This park is open Daylight Hours Only
and the Collection of Specimens, Either Biological, Cultural, or
Mineral is Strictly Prohibited. Please stay on designated
trails, see trail map by clicking here.
Remember as always, Leave No Trace.
Parking (included as a child waypoint) is available at
Rock House Parking Lot at N 39° 29.728, W 082° 36.740.
Rock House, The Bigger Opening
Rock House, The Smaller Opening
Inside or Under Rock House
Rock House is a natural arch and a natural tunnel but not a
natural bridge. It is by far the longest known natural arch and
natural tunnel in the State of Ohio. Also it is the only know arch
in the state with windows opening through the side.
How do you define a natural arch?
An arch is a horizontal remnant of exposed bedrock supported at two
opposing locations spanning an opening created by erosion. Not
every hole in the bedrock is considered an arch. An arch must meet
this measurement criterion. The span (horizontal measurement of the
opening) and clearance (vertical measurement of the opening) must
be greater than or equal to 6 feet with neither measurements being
less than a foot. Windows are openings that are smaller than
measurement criterion. They are also referred to as windows, gothic
windows, lighthouses, holes, and etc…
How do you define a natural tunnel?
A natural tunnel is a natural arch whose width, the horizontal
measurement perpendicular to the front face of the arch, is greater
than or equal to three times its span.
How do you define a natural bridge?
A natural bridge is a natural arch that spans a valley formed by
erosion. A natural bridge is always a natural arch, but a natural
arch may not be a natural bridge.
How did the Rock House form?
Rock House was formed by the widening of a vertical crack which
separated a large block of Black Hand sandstone from the main cliff
above a small tributary of Laurel Run. This created a passage
nearly 200’ long, 40’ high, and 20’ wide. Erosion and expansion of
secondary joints crossing the main joint has led to the formation
of Rock House’s distinctive gothic windows. This didn’t happen
overnight, it took millions of years during the Pleistocene epoch.
Some modern, in geological terms, history of Rock
Archaeological evidence from Rock House indicated that the
prehistoric Native American’s utilized this location. There are two
theories about the man-made indentations in the wall face. One is
the the Native Americans constructed these as small ovens to cook
meals. They also created troughs in the cave's floor, which
collected water to help provide the residences with a water supply.
The other is that they were turpentine stills. Turpentine was a
common resource for that local Native Americans. It was used as a
medicinal purpose, both internally and externally, for a wide
variety of illnesses and injuries. The Native Americans would place
bits of pitch pine wood in the indentations. On top of that they
would layer of flat sandstone. Finally on the top a fire would be
built. The heat would drive the sap out of the wood, which would
then flow through the channel and pour into waiting vessels.
In the not-so-distant past, Rock House was also referred to as
Robbers Roost. It seems that during the early 1800s local robbers,
horse thieves, murderers, and bootleggers made their temporary
residence here. The only know fatal bear attack in Hocking County
happed at Rock House. William Reynolds, one of the earliest
landowner used Rock House for a barn for his livestock. Then one
evening while walking to do his evening chores he encountered a
bear which attacked. Severely mauled, Mr. Reynolds survived and was
only to later to die from complications and infection the following
week. Then in 1835, an ambitious Colonel Rempel from Logan, Ohio
erected a hotel nearby hoping to capitalize of the increased tour
activity in the area. The hotel was had 16 rooms, a grand ballroom,
a horse livery, and a US Post Office. The hotel stood where the
present day shelter house stands.
To claim a find, please email me the answers
to the questions below. Also you will need to upload a
picture of yourself holding your GPSr with Rock House in the
background with your find log. Logs that do not follow the
finding requirements will be deleted.
Question 1: How many windows does Rock House have in it’s
Question 2: How many indentations in the wall face are
Question 3: At N 39° 29.862, W 082° 36.785 and N 39° 29.887, W
082° 36.765 are two additional geological features, what are
Camp, Mark J.
2006 Roadside Geology of Ohio.Mountain Publishing Company,
Hansen, Michael C.
1988 Natural Bridges in Ohio, Ohio Geology.
2007 Rock House. Ohio History Central,