| |
Note: Alaska and Hawaii are shown out of
position for reference only and are not to scale.
Blank
Illinois State Outline Map
Illinois is in the north-central U.S. and borders on
Lake Michigan.
Surrounding states are
Wisconsin to the north, Iowa
and Missouri to the west,
Kentucky to the south, and
Indiana to the east. Illinois
also borders Michigan, but only via a water boundary
in Lake Michigan.
Nearly the entire western boundary is the
Mississippi River,
except for a few areas where the river has changed
course.
Statistics
-
Illinois has a maximum north-south distance of 390 miles
and 210 miles east-west.
-
Total
area is 57,918 square miles, ranked 25th in size of the
50 states.
-
Water
area is 2,325 square miles; this is mainly
Lake Michigan.
-
Charles Mound is the
highest point in the state at 1,235 feet above sea
level.
-
The
Mississippi River at
Cairo, Illinois is the
lowest point, at 279 feet.
-
Average
elevation is 600 feet above sea level.
Geographical divisions
Illinois
has three major geographical divisions. The first is
Northern Illinois,
dominated by the
Chicago metropolitan area, including the city of
Chicago, its suburbs, and
the adjoining exurban area into which the metropolis is
expanding. As defined by the federal government, the Chicago
metro area includes a few counties in Indiana and Wisconsin
and stretches across much of northeastern Illinois, but not
as far as Rockford,
generally along Interstates 80
and 90. The region is
cosmopolitan, densely populated, industrialized, and settled
by a wide variety of ethnic groups.
Southward
and westward, the second major division is
Central Illinois, an area of
mostly flat prairie. The western
section (west of the Illinois River) was originally part of
the Military Tract of 1812
and forms the distinctive western bulge of state. Central
Illinois is known as the "Land of
Lincoln", it is characterized by small towns and
mid-sized cities. Agriculture, particularly
corn and soybeans, figures
prominently. Major cities include Peoria,
Springfield (the state
capital), and the twin cities of
Champaign and
Urbana (home of the
University of Illinois).
The third
division is Southern Illinois,
comprising the area south of U.S.
Route 50, and including
Little Egypt, near the juncture of the
Mississippi River and
Ohio River. This region can be
distinguished from the other two by its warmer climate,
different mix of crops (including some
cotton farming in the past), more rugged unglaciated
topography, as well as small-scale oil deposits and
coal mining. The area is a little more
populated than the central part of the state with the
population centered in two areas: the Greater St. Louis
Metropolitan Area (the Illinois suburbs of St. Louis are
known as "The Metro-East") and the
in Carbondale, Marion, West Frankfort, Herrin, Murphysboro,
Carterville, Johnston City area which is home to a little
over 180,000 residents.
Collectively, central and southern Illinois are often
referred to within Illinois as "downstate Illinois".
Sometimes all of Illinois outside of the Chicago metro area
is referred to as "downstate" for cultural reasons.
McLean County is the
largest county in terms of land area, at 1,184 sq mi., while
Cook County is the
largest county in terms of population, at 5,327,777 (both
figures are as of 2004).
In extreme
northwestern Illinois the
Driftless Zone, a region of unglaciated and therefore
higher and more rugged topography, occupies a small part of
the state. Charles Mound,
located in this region, is the state's highest elevation
above sea level.
The
Shawnee Hills arise in southern
Illinois. The Illinoian
glaciation period, about 100,000 years before present,
climbed the northern face of the Shawnee Hills, but did not
reach the summit. Most of the Shawnee Hills is therefore
unglaciated.
The
floodplain on the Mississippi River from
Alton to the
Kaskaskia River is the
American Bottom, and is the
site of the ancient city of Cahokia,
and was a region of early French settlement, as well as the
site of the first state capital, at
Kaskaskia.
The extreme
southern tip of Illinois is in the
Gulf Coastal Plain.
Political geography
The city of
Chicago and some of its older suburbs are heavily
Democratic.
While this tendency has historically been balanced by
Republican
voters in the suburbs, Democrats have significantly
increased their suburban support in the past decade. Central
Illinois' largely rural character helps to sustain a largely
Republican voting pattern and widespread antipathy toward
Chicago. The combination of poorer soil, coal mining and
industrialization has caused the southern region to lean
Democratic politically, especially in the urbanized region
around Saint Louis,
Missouri.
Rockford, Illinois is
known as a center of liberal
"gypsy moth" Republicans.
Geology
Illinois is
mainly covered with soil, hundreds of feet thick in many
places. Much of this soil is called, appropriately, "Illite",
and is the most common type of soil on the planet. The
visible geology of the State is therefore mainly
Quaternary, with rocks buried
deeply. The wealth of the State mainly arises from this
abundance of soil.
Illinois is
a major coal-producing state. Much of
the bedrock surface is of
Pennsylvanian age, including "cyclothemes", regular
sequences of limestone, shale and coal layers. Newer rocks
may have once existed in the State, but these have been
removed by repeated epochs of glaciation. Only tiny areas of
newer bedrock exist. The chance of finding dinosaur bones in
Illinois is almost nil: the Pennsylvanian rocks were here
before the dinosaurs.
Galena, a lead
ore, has been mined in the northwest corner of the State.
The ore was processed around Peru,
Illinois, where river transport was available to bring
the ore to a source of coal. About six tons of coal are
needed for each ton of ore.
Fluorite, calcium fluoride, is the
State mineral. It is mined in the southeastern portion of
the State, around Metropolis.
Fluorine gas is produced from fluorite. This is used in the
production of uranium
hexafluoride at the gaseous
diffusion plant in Paducah,
Kentucky.
Geodes can be found in the older
Mississippian outcroppings
along the Mississippi River.
Igneous intrusions are found in the
far southern areas of the State. Ages ago North America
began to split roughly along the lines of the Ohio and
Mississippi Rivers. Igneous rock flowed up into fissures, as
a new ocean began to form. Had this continued, Illinois
might have resembled the
Arabian Peninsula, a broken terrain between two
continents. This split, however, failed: the continent
reclosed, leaving only a few igneous intrusions, and some
oil fields, as evidence that it happened.
North of
the Illinois River the bedrock
surface is much older. Here the surface is sandstone that
was deposited when the Earth was very young. This sandstone
yields ancient sand that is very useful in the production of
glass, and in making molds for metal castings.
Coal
The
majority of Illinois surface bedrock
belongs to the Pennsylvanian
period, particularly the downstate region. About 68% of the
state has coal-bearing strata of this
geologic period. According to the Illinois State Geological
Survey, 211 billion tons of
bituminous coal are estimated to lie under the surface,
having a total heating value greater than the estimated oil
deposits in the Arabian
Peninsula. This coal has a high sulfur
content, which requires special equipment to reduce air
pollution.
Rivers
Illinois is
mainly bounded by rivers, and the
Illinois River bisects the state. A few rivers,
including the Fox and
Rock Rivers enter the
State from Wisconsin, but lose their identity before, or
upon, exiting the State. The
Iroquois and Kankakee
arise in Indiana, but lose their
identity before reaching the
Mississippi. The North Fork of the Vermilion River
arises in Indiana, but joins the
Vermilion, which exits the state before joining the
Wabash River in Indiana.
Groundwater
Subsurface
water is generally plentiful in Illinois. However, irregular
gravel deposits from glaciation may lead to difficulties
predicting depth of the water table.
The
Mahomet Aquifer is a large
aquifer used as a source for public water supply by many
communities in Central Illinois.
Flora and fauna
Large
mammal species currently found in
Illinois include whitetail deer
and coyote, with the latter becoming
urbanized in the Chicago area, as
well as common in the rural areas. Furbearers commonly found
include opossum,
raccoon, mink,
red and gray foxes, and
muskrat. Commonly seen lagomorphs
include the cottontail rabbit
and commonly seen rodents include
squirrels. Game birds found include
Canada goose,
mallard duck,
ruffed grouse,
wild turkey, and
bobwhite quail. The
cardinal is the official
state bird. The state has approximately 300 species of
birds, many of which migrate on the
Mississippi Flyway.
Extensive wetland restoration along the
Mississippi River and
Illinois River are attracting
many species.
About two
thirds of the state was originally prairie, with much of the
area converted to rowcrop farming, while the southern third
of the state remains heavily forested with
oak, hickory, and
maple. Also, several prairie plants.
Especially in the northern third of the state, intensive
agriculture has made some species rare, while population
numbers are increasing in the less-developed south. Large
mammals no longer found in
Illinois include American Bison,
Gray Wolf,
American Black Bear, and
elk.
Climate
Illinois
has a continental climate,
with large temperature extremes not moderated by either
mountains or oceans. Weather is influenced primarily by cold
Canadian Arctic air in the winter, and warm, humid air from
the Gulf of Mexico in the
summer. High temperatures in the south of the state are
about 10 to 12 °F. warmer than the north. Average annual
temperature is 47 °F. in the north and 58 °F. in the south.
Temperatures greater than 90 °F. occur about 45 days per
year in the south, and 12 days per year in the north.
Temperatures below zero °F. occur one day or less per year
in the south, and 12 days per year in the north. Annual
rainfall is 34 inches in the north and 46 inches in the
south.
Prevailing
winds are from the west. Average wind
speeds "blowing off of the prairie"
are greater in the Chicago area.
Statewide, the wind speeds average 8 to 12 miles per hour,
and is greater in the winter than in summer.
Snowfall
averages 30 inches in the north and 10 inches in the south,
although the actual snowfalls vary greatly by year. In some
years, southern Illinois receives very little snowfall, and
may never get typical winter weather.
Most of the
state has four distinct seasons, except for the Chicago
area, where the winds "blow the leaves off of the trees": it
goes almost from summer to winter without an autumn in
between. The southernmost part of the state is heavily
forested and the trees are noted for having beautiful
fall colors.
Tornadoes are a common hazard,
primarily in the central part of the state, with peak months
in June and April. Freezing rain is most common in central
Illinois.
Border anomalies
The
Mississippi River is the
nominal western boundary of the state, except for locations
where the river has changed course.
Kaskaskia, Illinois, the
first state capital, is now west of the river. The
Mississippi, due to a flood, destroyed the old town of
Kaskaskia, and occupies what was the lower channel of the
Kaskaskia River. A portion of
Missouri is east of the river, near
Grand Tower, Illinois.
Similar "avlusions" are found along the
Ohio River border with
Kentucky and the
Wabash River border with
Indiana.
Interactive Illinois State Map
Explore the state of Illinois with the dynamic map below. You can
zoom, pan and even get a satellite map view.
Move your cursor over the markers on the map to
learn more about Illinois.
State
Index |
Information
|
Fast Facts
|
Geography
|
Government
|
Economy |
History
|
|
