Mill Bluff State Park
Encyclopedia
Mill Bluff State Park is a state park
of Wisconsin
, USA, preserving several prominent sandstone bluffs. The park is located in eastern Monroe
and western Juneau
counties, near the village of Camp Douglas
, and is a unit of the Ice Age National Scientific Reserve
. The park protects several sandstone bluffs between 80 and 200 ft (24.4 and 61 m) high which were islands 12,000 years ago in Glacial Lake Wisconsin
. As a result these bluffs are steep and angular, dissimilar to the rounded terrain more typical of the eastern half of the United States. The bluffs served as landmarks both to early pioneers and to travelers today on Interstate 90
/94
which passes through the park.
. The park office is at its foot, and the campground is just to the west. Bee Bluff, although smaller and only 60 feet (18.3 m) high, is the most visible bluff from the interstate, as it stands adjacent to the westbound lanes. To the north is 170 feet (51.8 m) Camels Bluff, actually two separate outcroppings which together resemble the humps of a camel. Nearby are Devils Monument and a 40 feet (12.2 m) high pinnacle called Cleopatra's Needle. The other, less accessible bluffs are Round Bluff and Sugar Bowl Bluff to the south, 140 feet (42.7 m) Wildcat Bluff and Bear Bluff to the north, and 199 feet (60.7 m) Long Bluff to the northeast. Also in the northeast is Ragged Rock, an 80 feet (24.4 m) tall former bluff whose protective cap was worn away and is eroding into a conical mound.
. Stratigraphically, the stone of the bluffs is part of the Galesville Member of the Dresbach Group. Sandstone from the Ironton Member of the Franconia Formation, which is more solidly concreted, tops each bluff. This capping layer helped protect the softer stone below it from erosion. Similar structures elsewhere in Wisconsin would have been bulldozed away by glaciers, but these bluffs lie in the Driftless Area; that part of the American Midwest which was never glaciated. The bluffs are all outliers of the Franconia Cuesta
to the south.
During the last ice age
a tongue of ice dammed the Wisconsin River
, causing the water to back up into Glacial Lake Wisconsin. It is estimated that the lake was about 60 to 80 ft (18.3 to 24.4 m) deep in this area, so the taller bluffs became islands while the shorter ones would have been entirely underwater. For the 300 years of the lake's existence waves eroded the edges of the bluffs, giving them their distinctive steep sides. Thus in a geological sense the bluffs are sea stacks
because they formed in a body of water. In practice the larger formations are described as mesa
s, the medium-sized ones as butte
s, and the smallest as a pinnacle.
The flat ground in the park consists of finely sorted sediments that settled to the bottom of Glacial Lake Wisconsin. Glacial erratic
s have been found on the former lakebed, which are explained as rocks which were embedded in iceberg
s that melted as they were floating in the lake.
The park is mostly forested, with northern pin oak
, jack pine
, red pine
, eastern white pine
, and white oak
dominant.
s shaped like bird tracks, contemporaneous with the Roche-a-Cri Petroglyphs
in Roche-a-Cri State Park
.
The diaries and journals of west-bound settlers often mention these bluffs. A sawmill
was operated in the vicinity, after which Mill Bluff was named.
Mill Bluff and a small area at its foot was proclaimed a state park on August 13, 1936. Mill Bluff State Park was added to the Ice Age National Scientific Reserve in May 1971. The park's boundaries were expanded to include the other bluffs later. In 2002 a portion of the park containing all of the major bluffs received a further level of protection as Mill Bluff State Natural Area.
_map.jpg)
Mill Bluff State Park is open from May to September. Small game hunting is permitted in sections of the park from November 1 to December 15, and deer hunting during a shorter period.
The park's small campground has 21 sites, 6 with electrical hookups. Amenities are primitive, with pit toilets and no showers. Potable water is available from hand pump
s.
Swimming is available in a 2.5 acres (1 ha) spring
-fed lake south of the campground. Sand has been added to make a 250 feet (76.2 m) beach.
A 0.4 miles (643.7 m) nature trail circles the base of Mill Bluff. 223 stone steps built by the Works Progress Administration
in the 1930s lead to its top. 0.8 miles (1.3 km) north on County Road W (Funnel Road) is a pullout for the 1.25 miles (2 km) Camels Bluff loop trail, which passes between the two sections of Camels Bluff and leads past the base of Devils Monument and Cleopatra's Needle.
Because the bluffs are formed of soft sandstone and geologically unique, all climbing is prohibited.
State park
State parks are parks or other protected areas managed at the federated state level within those nations which use "state" as a political subdivision. State parks are typically established by a state to preserve a location on account of its natural beauty, historic interest, or recreational...
of Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
, USA, preserving several prominent sandstone bluffs. The park is located in eastern Monroe
Monroe County, Wisconsin
Monroe County is a county in the U.S. state of Wisconsin. As of 2000, the population was 40,899. Its county seat is Sparta.-Geography:According to the U.S...
and western Juneau
Juneau County, Wisconsin
Juneau County is a county located in the U.S. state of Wisconsin. As of the 2000 census, the population was 24,316. Its county seat is Mauston. It should not, however, be confused with the city of Juneau, Wisconsin, to which it has no connection.-Geography:...
counties, near the village of Camp Douglas
Camp Douglas, Wisconsin
Camp Douglas is a village in Juneau County, Wisconsin, United States. The population was 592 at the 2000 census. Camp Douglas is home to Volk Field Air National Guard Base.-History:...
, and is a unit of the Ice Age National Scientific Reserve
Ice Age National Scientific Reserve
The Ice Age National Scientific Reserve is a collection of nine sites in Wisconsin that preserve geological evidence of glaciation. The reserve was created in 1971 to protect the scientific and scenic value of the landforms...
. The park protects several sandstone bluffs between 80 and 200 ft (24.4 and 61 m) high which were islands 12,000 years ago in Glacial Lake Wisconsin
Glacial Lake Wisconsin
Glacial Lake Wisconsin was a prehistoric proglacial lake that existed from approximately 19,000 to 15,000 years ago, at the end of the last ice age, in the central part of present-day Wisconsin in the United States....
. As a result these bluffs are steep and angular, dissimilar to the rounded terrain more typical of the eastern half of the United States. The bluffs served as landmarks both to early pioneers and to travelers today on Interstate 90
Interstate 90
Interstate 90 is the longest Interstate Highway in the United States at . It is the northernmost coast-to-coast interstate, and parallels US 20 for the most part. Its western terminus is in Seattle, at Edgar Martinez Drive S. near Safeco Field and CenturyLink Field, and its eastern terminus is in...
/94
Interstate 94
Interstate 94 is the northernmost east–west Interstate Highway, connecting the Great Lakes and Intermountain regions of the United States. I-94's western terminus is in Billings, Montana at a junction with Interstate 90; its eastern terminus is the U.S...
which passes through the park.
Geography
There are 10 named bluffs in the park. Mill Bluff, 120 feet (36.6 m) high, is between the interstate and U.S. Route 12U.S. Route 12
U.S. Route 12 or US 12 is an east–west United States highway, running from Grays Harbor on the Pacific Ocean, in the state of Washington, to downtown Detroit, for almost . As a thoroughfare, it has mostly been supplanted by I-90 and I-94, but remains an important road for local travel.The...
. The park office is at its foot, and the campground is just to the west. Bee Bluff, although smaller and only 60 feet (18.3 m) high, is the most visible bluff from the interstate, as it stands adjacent to the westbound lanes. To the north is 170 feet (51.8 m) Camels Bluff, actually two separate outcroppings which together resemble the humps of a camel. Nearby are Devils Monument and a 40 feet (12.2 m) high pinnacle called Cleopatra's Needle. The other, less accessible bluffs are Round Bluff and Sugar Bowl Bluff to the south, 140 feet (42.7 m) Wildcat Bluff and Bear Bluff to the north, and 199 feet (60.7 m) Long Bluff to the northeast. Also in the northeast is Ragged Rock, an 80 feet (24.4 m) tall former bluff whose protective cap was worn away and is eroding into a conical mound.
Natural history
The bluffs in the park, and others nearby, are formed of Late Cambrian sandstoneSandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
. Stratigraphically, the stone of the bluffs is part of the Galesville Member of the Dresbach Group. Sandstone from the Ironton Member of the Franconia Formation, which is more solidly concreted, tops each bluff. This capping layer helped protect the softer stone below it from erosion. Similar structures elsewhere in Wisconsin would have been bulldozed away by glaciers, but these bluffs lie in the Driftless Area; that part of the American Midwest which was never glaciated. The bluffs are all outliers of the Franconia Cuesta
Cuesta
In structural geology and geomorphology, a cuesta is a ridge formed by gently tilted sedimentary rock strata in a homoclinal structure. Cuestas have a steep slope, where the rock layers are exposed on their edges, called an escarpment or, if more steep, a cliff...
to the south.
During the last ice age
Wisconsin glaciation
The last glacial period was the most recent glacial period within the current ice age occurring during the last years of the Pleistocene, from approximately 110,000 to 10,000 years ago....
a tongue of ice dammed the Wisconsin River
Wisconsin River
-External links:* * * , Wisconsin Historical Society* * * *...
, causing the water to back up into Glacial Lake Wisconsin. It is estimated that the lake was about 60 to 80 ft (18.3 to 24.4 m) deep in this area, so the taller bluffs became islands while the shorter ones would have been entirely underwater. For the 300 years of the lake's existence waves eroded the edges of the bluffs, giving them their distinctive steep sides. Thus in a geological sense the bluffs are sea stacks
Stack (geology)
A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, isolated by erosion. Stacks are formed through processes of coastal geomorphology, which are entirely natural. Time, wind and water are the only factors involved in the...
because they formed in a body of water. In practice the larger formations are described as mesa
Mesa
A mesa or table mountain is an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape....
s, the medium-sized ones as butte
Butte
A butte is a conspicuous isolated hill with steep, often vertical sides and a small, relatively flat top; it is smaller than mesas, plateaus, and table landform tables. In some regions, such as the north central and northwestern United States, the word is used for any hill...
s, and the smallest as a pinnacle.
The flat ground in the park consists of finely sorted sediments that settled to the bottom of Glacial Lake Wisconsin. Glacial erratic
Glacial erratic
A glacial erratic is a piece of rock that differs from the size and type of rock native to the area in which it rests. "Erratics" take their name from the Latin word errare, and are carried by glacial ice, often over distances of hundreds of kilometres...
s have been found on the former lakebed, which are explained as rocks which were embedded in iceberg
Iceberg
An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...
s that melted as they were floating in the lake.
The park is mostly forested, with northern pin oak
Northern Pin Oak
Quercus ellipsoidalis, the Northern Pin Oak or Hill's Oak, is an oak in the red oak section Quercus sect. Lobatae. It is mainly native to the northern midwest United States, and also in the southeast and southwest of Ontario, Canada. It occurs on dry, sandy, usually acidic soils. Although the name...
, jack pine
Jack Pine
Jack pine is a North American pine with its native range in Canada east of the Rocky Mountains from Northwest Territories to Nova Scotia, and the northeast of the United States from Minnesota to Maine, with the southernmost part of the range just into northwest Indiana...
, red pine
Red Pine
Pinus resinosa, commonly known as the red pine or Norway pine, is pine native to North America. The Red Pine occurs from Newfoundland west to Manitoba, and south to Pennsylvania, with several smaller, disjunct populations occurring in the Appalachian Mountains in Virginia and West Virginia, as well...
, eastern white pine
Eastern White Pine
Pinus strobus, commonly known as the eastern white pine, is a large pine native to eastern North America, occurring from Newfoundland west to Minnesota and southeastern Manitoba, and south along the Appalachian Mountains to the northern edge of Georgia.It is occasionally known as simply white pine,...
, and white oak
White oak
Quercus alba, the white oak, is one of the pre-eminent hardwoods of eastern North America. It is a long-lived oak of the Fagaceae family, native to eastern North America and found from southern Quebec west to eastern Minnesota and south to northern Florida and eastern Texas. Specimens have been...
dominant.
Cultural history
Several of the bluffs bear 400-year-old petroglyphPetroglyph
Petroglyphs are pictogram and logogram images created by removing part of a rock surface by incising, picking, carving, and abrading. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions of the technique to refer to such images...
s shaped like bird tracks, contemporaneous with the Roche-a-Cri Petroglyphs
Roche-a-Cri Petroglyphs
The Roche-a-Cri Petroglyphs, also known as the Friendship Glyphs, are a Registered Historic Place in Roche-a-Cri State Park, near Friendship, Wisconsin. They consist of Oneota rock art, mostly petroglyphs resembling birds, canoes and geometric designs. They were added to the National Register of...
in Roche-a-Cri State Park
Roche-a-Cri State Park
Roche-a-Cri State Park is a state park north of Adams and Friendship in central Wisconsin. The park, in area, was established in 1949....
.
The diaries and journals of west-bound settlers often mention these bluffs. A sawmill
Sawmill
A sawmill is a facility where logs are cut into boards.-Sawmill process:A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end....
was operated in the vicinity, after which Mill Bluff was named.
Mill Bluff and a small area at its foot was proclaimed a state park on August 13, 1936. Mill Bluff State Park was added to the Ice Age National Scientific Reserve in May 1971. The park's boundaries were expanded to include the other bluffs later. In 2002 a portion of the park containing all of the major bluffs received a further level of protection as Mill Bluff State Natural Area.
Recreation
The park's small campground has 21 sites, 6 with electrical hookups. Amenities are primitive, with pit toilets and no showers. Potable water is available from hand pump
Hand pump
Hand pumps are manually operated pumps; they use human power and mechanical advantage to move fluids or air from one place to another. They are widely used in every country in the world for a variety of industrial, marine, irrigation and leisure activities...
s.
Swimming is available in a 2.5 acres (1 ha) spring
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
-fed lake south of the campground. Sand has been added to make a 250 feet (76.2 m) beach.
A 0.4 miles (643.7 m) nature trail circles the base of Mill Bluff. 223 stone steps built by the Works Progress Administration
Works Progress Administration
The Works Progress Administration was the largest and most ambitious New Deal agency, employing millions of unskilled workers to carry out public works projects, including the construction of public buildings and roads, and operated large arts, drama, media, and literacy projects...
in the 1930s lead to its top. 0.8 miles (1.3 km) north on County Road W (Funnel Road) is a pullout for the 1.25 miles (2 km) Camels Bluff loop trail, which passes between the two sections of Camels Bluff and leads past the base of Devils Monument and Cleopatra's Needle.
Because the bluffs are formed of soft sandstone and geologically unique, all climbing is prohibited.
External links
- Mill Bluff State Park
- Mill Bluff State Natural Area
- Mill Bluff geology from the National Park Service