Ecological, Institutional,
and Economic History
of the
Upper Mississippi River
St. Marys University of
Minnesota
July 17, 2000
The Ecological,
Institutional, and Economic History of the Upper Mississippi River
was prepared by Dr. Calvin Fremling and Mr. Barry Drazkowski of the Resource
Studies Center St. Marys University of Minnesota
under a grant from the Environmental Protection Agency. The grant code number is CP995037-01-0.
ACKNOWLEDGEMENTS............................................................................................................................................................. 4
INTRODUCTION............................................................................................................................................................................ 5
EARLY GEOLOGIC HISTORY OF THE UPPER MISSISSIPPI RIVER BASIN................................................................ 5
HOW
PLEISTOCENE GLACIATION DETERMINED THE MODERN UPPER MISSISSIPPI RIVER DRAINAGE
SYSTEM 6
Changing river courses........................................................................................................................................................ 6
Terraces................................................................................................................................................................................... 8
The remarkable Unglaciated Area...................................................................................................................................... 8
POSTGLACIAL
CLIMATE AND ITS ECOLOGICAL IMPACTS.......................................................................................... 8
PREHISTORIC PEOPLES............................................................................................................................................................ 9
THE MYTH OF THE ECOLOGICALLY BENIGN NATIVE AMERICAN............................................................................. 9
VEGETATION AND WILDLIFE AT THE TIME OF AMERICAN-EUROPEAN SETTLEMENT.................................... 10
SETTING THE STAGE FOR THE CAUCASIAN INVASION............................................................................................... 11
PRESETTLEMENT PLANT COMMUNITIES......................................................................................................................... 12
EARLY EXPLOITATION OF WILDLIFE RESOURCES...................................................................................................... 13
MISMANAGEMENT OF THE LAND........................................................................................................................................ 13
Impacts of agriculture............................................................................................................................................................. 13
We cut the top off Minnesota and Wisconsin
and sent it down the river..................................................................... 14
The pearl button industry....................................................................................................................................................... 15
IMPROVING THE RIVER........................................................................................................................................................... 15
Early canal construction, dredging, and
snag clearing.................................................................................................. 16
The 4 1/2-ft and 6-ft channel projects.................................................................................................................................. 16
Connecting the Mississippi with the Great
Lakes............................................................................................................. 17
Headwaters reservoirs............................................................................................................................................................. 17
Taming the Des Moines Rapids............................................................................................................................................ 17
The Hydroelectric Facility and Lock and Dam
19, Keokuk, IA.................................................................................... 18
The 9-ft channel........................................................................................................................................................................ 19
CONVERSION OF THE FLOODPLAIN TO AGRICULTURE............................................................................................. 20
POLLUTION.................................................................................................................................................................................. 21
INTRODUCTIONS OF EXOTICS............................................................................................................................................. 22
URBAN SPRAWL........................................................................................................................................................................ 23
IMPACTS OF RECREATIONAL USE...................................................................................................................................... 23
ECOLOGICAL IMPACTS OF CHANNELIZATION............................................................................................................. 24
Impacts of nine-foot channel................................................................................................................................................. 24
Floodplain forests.................................................................................................................................................................... 27
Changing species composition of floodplain
forests........................................................................................................ 28
Aquatic vegetation................................................................................................................................................................... 29
Bottom-dwelling macroinvertebrates.................................................................................................................................. 31
Native freshwater mussels (clams)........................................................................................................................................ 32
Fingernail clams...................................................................................................................................................................... 32
Hexagenia mayflies................................................................................................................................................................. 32
Fishes.......................................................................................................................................................................................... 32
Flooding.................................................................................................................................................................................... 32
Sedimentation........................................................................................................................................................................... 32
REFUGES........................................................................................................................................................................................ 32
HABITAT MANAGEMENT AND MITIGATION.................................................................................................................... 32
THE GREAT STUDIES................................................................................................................................................................. 32
GREAT I, II, and III................................................................................................................................................................ 32
The Master Plan....................................................................................................................................................................... 32
THE ENVIRONMENTAL MANAGEMENT PROGRAM....................................................................................................... 32
Habitat Rehabilitation and Enhancement
Program........................................................................................................ 32
Long Term Resource Monitoring Program........................................................................................................................ 32
THE GREAT COORDINATION NETWORK.......................................................................................................................... 32
THE FUTURE OF THE RIVER SYSTEM.................................................................................................................................. 32
ANNOTATED BIBLIOGRAPHY............................................................................................................................................... 32
The Resource Studies Center wishes to
acknowledge Dr. Calvin Fremling for his efforts as the primary author of the
Ecological, Institutional, and Economic History of the Upper Mississippi
River. We also wish to acknowledge and
express our appreciation to the Environmental Protection Agency for their
support in preparing this report. The
information contained within this document can play an important role in
understanding our past in making decisions for the future Mississippi River.
The
Mississippi is not just any river; it is the "Mighty Mississippi," a
busy, vital, intracontinental water highway that connects North America's
"breadbasket" with the rest of the world. The Mississippi River
drainage basin includes the agricultural heartland of the United States,
supermarket to the world. Its fertile
soils, some of the world's richest, feeds one in every 12 of the world's
people.
Today, most
of the Mississippi River south of St. Paul, Minnesota, is a "working river,"
a water highway to the sea dominated by powerful, ponderous towboats. On their way downstream, the big ones may
wrestle six acres of grain-laden barges toward the deep-water ports of Baton
Rouge and New Orleans where the corn and soybeans will be transferred to
ocean-going freighters for worldwide distribution. On their return trip, the
towboats may push barges of fertilizer for the farmers that grew the grain, or
fuel for cars, trucks, and farm machinery.
Coal is shuttled upstream, as well as downstream, to supply power plants
that furnish most of the electrical energy for cities, industries, and farms.
Commercially,
the Mississippi is one of the world's most important and severely regulated
rivers. "Regulated river" is
a recent euphemism describing rivers that are dammed and constrained. By definition, the Upper Mississippi River
is the reach from St. Anthony Falls in Minnesota to the mouth of the Ohio River
at Cairo, Illinois. The Mississippi was
modified to improve navigation as early as 1829 when snag removal was begun on
the Lower Mississippi. Canals, cut
through the Keokuk Rapids and Rock Islands Rapids, were completed in 1839 and
1854, and the river was intensively channelized with wing dams, closing dams,
and shoreline protection during the 1878 - 1912 period. With minor exceptions (St. Anthony Falls,
Rock Island Rapids, Keokuk Rapids, and Chain of Rocks at St. Louis), most rocks
larger than volleyballs - from Minneapolis to Cairo - were placed there by the
U.S. Army Corps of Engineers or the Corps' contractors as part of early
channelization projects. In the past
decade, additional rockwork has been done for habitat enhancement.
Broad,
shallow impoundments were created on the Upper Mississippi when 29 navigation
dams were constructed, mainly during the 1930's, to create a slack-water
navigation channel 9 feet deep between St. Louis and Minneapolis. River travelers are usually surprised at the
width of the Upper Mississippi in its impounded reaches where it is much wider
(but much shallower) than it is at St. Louis or New Orleans where the river is
undammed. The Upper Mississippi River
contains some of the planet's most productive ecosystems, and most of the river
above St. Louis supports intensive recreational use.
Because the impoundments
alone are insufficient to maintain the 9-foot commercial channel, the river's
main channel is routinely dredged in some reaches. Almost all sand islands along the main channel have been placed
there as result of dredging. In recent
years, attempts have been made to minimize the adverse environmental impacts of
this practice.
Dams and
levees, which aid navigation and floodplain agriculture, have reduced the
river's natural ability to create habitat for fish and wildlife during periods
of high flow. Yet, floods have
increased in frequency and severity.
Navigation impoundments, side channels, and sloughs are filling with
sediment - and the rate of filling may be exacerbated by proposed increases in
commercial traffic. Some river reaches are severely polluted. Exotic plants and animals are competing with
native species, and whole ecosystems seem to be unraveling. Yet, we are exponentially increasing our
demands on this diminishing resource.
While the myriad manmade problems affecting the Mississippi are of
recent origin, they have their foundation in the natural forces that shaped the
river and its enormous watershed. A
basic understanding of that geological history is necessary to appreciate
today's river and its ills.
EARLY
GEOLOGIC HISTORY OF THE UPPER MISSISSIPPI RIVER BASIN
Lakes are
temporary features, but rivers are virtually immortal, and they are relentless
shapers of the land. Mountains may rise
up and detour them, but they continue to flow.
At the
beginning of the Cambrian period, about 570 million years before present
(B.P.), the North American continent was smaller than it is now and was mainly
above sea level. At about that time,
the earth's crust began to subside throughout much of the interior of the
continent, causing oceans to advance over the low-lying, bleak, barren, land
surface of the area now drained by the Mississippi River and its tributaries.
As the sea
advanced, its pounding surf attacked the uplands and stripped off rock debris
from the severely weathered land areas where a cover of protective plants had
not yet evolved. Beach zones were
high-energy environments where wave action and currents continued the disintegration
of the rock debris, winnowing it, and depositing the coarsest particles in the
surf areas as clean, well-sorted beds of sand that ultimately formed
sandstones. Silt and clay were wafted
out into quiet, deeper waters where they settled and were compressed to form
shales. Abundant lime-secreting
organisms produced deposits that formed limestones and dolomites in warm
shallow water, with little input of sand, silt or clay. During the ensuing 500 million years the
shallow Epicontinental Sea served as a collection basin for sediments that
eroded and washed outward from primordial uplands and mountain ranges.
The oceans
did not advance at a uniform rate.
Forces deep within the earth caused mild subsidence or downwarping in
some areas and uplifts in adjacent areas, causing shorelines to advance and
retreat. This caused distinctive cyclic
patterns in the sediment deposits, and ultimately in the sedimentary rocks that
were formed from them. A sandstone
stratum, for example, may be bounded above and below by shale or
limestone. The layers of sedimentary
rocks are now hundreds of feet thick in southern Minnesota and thousands of
feet thick in the far west and deep south.
It is
generally accepted that during this interval of inundation North America
straddled the equator and subsequently became part of the supercontinent
"Pangaea." Nearly all of the marine fossils found in central North
America are of animals that flourished in warm, tropical seas.
Geologic
forces during the westward drift of the North American plate caused the general
uplifting of the North American continent from the Mississippi River to the
Pacific Ocean. To the east of the Rocky
Mountains, a great sedimentary rock plateau rose from the sea constructing a
stable platform of sedimentary strata, bounded on the west by the youthful
Rocky Mountains and on the east by the much older southern Appalachian
Mountains.
The strata
along the Upper Mississippi River are very stable. They were originally laid flat, and for the most part remain that
way, but they do bulge upward, reaching their highest elevations near La
Crosse, Wisconsin. They then tilt
downward to the north, west and south, buried beneath younger strata.
It is within
the easily erodible sedimentary platform that most of the Mississippi River and
most of its tributaries now flow.
Eastern tributaries drain heavily vegetated uplands. Their clear waters run through well-defined
valleys. Western rivers drain the
Rockies through semi-arid, sparsely vegetated, highly erodible areas. Although
dams presently intercept much of their sediment load, western tributaries still
provide the most silt to the Mississippi.
HOW
PLEISTOCENE GLACIATION DETERMINED THE MODERN UPPER MISSISSIPPI RIVER DRAINAGE
SYSTEM
Soon after
discovery of continental glaciation in the last century, geologists learned
that there were at least four major glacial periods during the Pleistocene
epoch that began about 1.8 million years B.P.
The progressively younger Nebraskan, Kansan, Illinoian, and Wisconsin
glaciations are each named for the state where their maximum development is
evidenced. Most evidence for
continental glaciation came from studies of the continents themselves, but
oceanographers have recently amassed a detailed glacial chronology from cores
of deep-sea sediments. Each glaciation
was followed by an interglacial interval in which the climate became similar to
today's.
During
preglacial time (late Tertiary), the Central Lowlands of the northern United
States had been drained principally by streams flowing northward into Canada.
The northern tributaries of the Missouri River drained into the Arctic Ocean
via Hudson Bay. The northern tributaries of the present Ohio River flowed
northward across Pennsylvania, Ohio, and Indiana into the St. Lawrence River
system that flows into the North Atlantic Ocean.
Nebraskan,
Kansan, and Illinoian glaciers sequentially advanced as far south as the
approximate present position of the Missouri and Ohio Rivers. The modern courses of these rivers were
determined as vast quantities of meltwater collected along the leading edge of
the glaciers. Because northward flow
was restricted by ice, the rivers of meltwater flowed in a general southerly
direction and became tributaries of the Mississippi River.
The
"Wisconsin" glacial, that began about 100,000 years B.P. and ended
about 10,000 years B.P., was the last major glaciation in North America, and is
the best understood because its deposits are widely exposed and have not been
disturbed by subsequent glaciers.
Worldwide,
about 20 million square miles of the earth's surface were covered during
Pleistocene glacial maximums. As much
as 30 percent of Earth's land surface was ice-covered, compared with about 10
percent today. The average thickness of
the ice sheets was about one mile, causing sea levels to be lowered about 450
feet. Expansive tracts of the
continental shelves of North America were then dry land. Today, commercial fishermen trawling along
the eastern seaboard often snag tree stumps from forests that grew there.
Continental
glaciation and commensurate changes in ocean levels greatly accelerated
erosional processes in the Northern Hemisphere. Worldwide, falling ocean levels caused river gradients to become
steeper. Consequently, the rivers ran
faster and were able to "degrade" or downcut through previously
deposited sediments. Rising ocean
levels, on the other hand, reduced the gradient of rivers, decreased their
sediment carrying capacity, and caused valley floors to rise or
"aggrade" as they became choked with sediment. This complex interplay of glaciation and
fluctuating ocean levels alternately caused master valleys and tributary
valleys to flush and to fill. In the case of the Mississippi River, the story
is more complex because the rapid draining of glacial lakes, impounded by
retreating glaciers late in the Wisconsin glacial, caused torrents of
sediment-free water to entrench the Upper Mississippi valley while the Lower
Mississippi valley was aggrading.
Evolution of
the modern Upper Mississippi River downstream from Minneapolis is generally
believed to have begun about 1,500,000 years ago when Nebraskan glacial ice, that
had approached from the west and northwest, displaced the Mississippi River
eastward from its northwest-southeast course through central Iowa to its
present location. As it flowed along
the eastern edge of the Nebraskan glacier as an "ice-border stream",
it incised a new channel through sedimentary rock strata, and establishing the
present general course of the Mississippi River from near the Twin Cities
southward to the Mississippi Embayment.
The general course of the Lower Mississippi is much older - probably as
old as the Atlantic Ocean. It has
probably flowed through the Mississippi Embayment - the sediment-filled
troughlike structure that reaches north from the Gulf of Mexico to Cairo,
Illinois - since the late Paleozoic Period over 250 million years ago.
As the
Wisconsin ice sheet retreated northward, it stood across the valley of the
Mississippi at St. Paul and discharged great quantities of water, gravel, sand,
silt, and clay down the valley. As the
valley floor of the main stem rose, the gradients of tributaries decreased
commensurately, causing them to drop their sediment loads. This, in turn, additionally elevated the
floors of tributary valleys, causing them to be flat and continuous with the
valley floor of the mainstem.
The greatest of
all Upper Mississippi floods began about 12,700 years ago when Glacial Lake
Agassiz, North America's largest glacial lake, spilled over its southern rim,
forming the torrential Glacial River Warren that carved the immense valley now
occupied by the Minnesota River. Lake
Agassiz served as the source of the Mississippi River for about the next 2,700
years, and was the hub of migration for cold-water fishes and many other
species of aquatic life that now live in the interior of Canada, the northern
United States, and much of Alaska.
With the
Great Lakes' outlet to the North Atlantic Ocean via the St. Lawrence River
blocked by ice during Wisconsin glaciation, the water level of Glacial Lake
Superior rose until it was four or five hundred feet higher than today's Lake
Superior. It spilled over its southern
rim, forming the Glacial St. Croix River that supplemented the flows of the
River Warren.
During the
time when the St. Lawrence outlet of the Great Lakes was blocked by ice, the
Mississippi River also received overflow of meltwater from Glacial Lake
Michigan via the Illinois River, and from Glacial Lake Erie via the Ohio
River. Flowing waters tend to transport
as much sediment as they can carry.
Sediment-poor water is called "hungry water" due to its great
erosive capacity. Because Glacial Lake
Agassiz and the Great Lakes served as settling basins for glacial sediments,
their overflows ran comparatively clear, and their hungry waters greatly
increased the erosive capacity of the Upper Mississippi River, enabling it to
export sediments faster than they could be supplied by tributaries. This resulted in the entrenching of the
Mississippi channel over 200 feet in some reaches.
As ice
retreated northward, Glacial Lake Agassiz drained to the north and east, and
the Great Lakes resumed their drainage via the St. Lawrence River into the
Atlantic Ocean. Relieved of their
massive burdens of ice, the glacial outlet channels of both Lake Agassiz and
the Great Lakes began to rebound, completing the beheading of the River Warren,
and the Glacial St. Croix, Illinois and Ohio Rivers. With the cessation of flows from its glacial tributaries, the Mississippi lost most of its ability to
transport sediments from steep-sloped tributaries, causing its valley to fill
to its present level as an overloaded braided stream.
The
Mississippi tended to entrench itself during the floods caused by the draining
of glacial lakes, but between floods the valley floor aggraded as tributaries
brought in more glacial drift than the Mississippi could carry away. The result was a succession of prominent,
bench-like terraces (remnants of the former flood plain)
flanking the
river from St. Anthony Falls to the mouth of the Ohio River.
The highest
terraces are evidence that the valley had aggraded to over 50 feet above its
present level prior to scouring by flows from the glacial rivers, which
entrenched the Mississippi valley, and secondarily caused the entrenchment of
flat tributary valley floors. Because
the terraces are nearly level, and less subject to flooding, they have been
used as locations for communities. They
are also used for agriculture, roads, railroads, and as home building sites. Native Americans used them for summer
encampments, especially if they occurred where a navigable tributary joined the
Mississippi.
The
remarkable Unglaciated Area
Near Red
Wing, Minnesota, the Mississippi enters the distinctive "Unglaciated
Area," a rugged landscape of stream-dissected rock strata of Paleozoic
Age. It includes parts of northeastern
Iowa, southeast Minnesota, northwest Illinois, and southwest Wisconsin. Glacier
after glacier approached this remarkable area, but left it virtually
unscathed. If the area had been
recently scoured by ice, its topography would not be nearly so rugged. The beautiful cliffs would have been erased.
Most of the
bluffland within the unglaciated area and along both sides of the river from
the Twin Cities all the way downriver to Cairo, Illinois, are marked by karst
landscape - characterized by sinkholes, caves, springs and disappearing
streams. The groundwater of the karst
region are extremely susceptible to pollution from farm fields, feedlot runoff,
failed sewage lagoons, and residential development.
POSTGLACIAL
CLIMATE AND ITS ECOLOGICAL IMPACTS
As glacial
ice retreated northward, climatic zones and vegetation also shifted to the
north. Deciduous forests, for example,
replaced Iowas coniferous forests,, and they, in turn, gave way to prairie
grasslands.
The climate
of immediately postglacial midwestern America has no modern analog. The present interglacial period, called the
"Holocene or Recent", was triggered by a gradual increase in the
earth's mean annual temperature for the first 4,000 or 5,000 years, culminating
in a period of temperatures higher than today called the
"Altithermal." The warmest
time interval in our interglacial, called the hypsithermal interval, was warmer
than now, and has no modern analog. It
began about 8,500 years B.P., lasted until about 5,000 years B.P., and was
followed by cooler temperatures that favored several episodes of advance and retreat
of mountain glaciers. Cold returned
about 1350 AD, causing the "Little
Ice Age" that lasted until about 1870 AD.
It caused the temporary expansions of glaciers and ice caps, and
southward shifts of vegetative zones - and it must have severely impacted
native Americans. It is interesting to
note that much of the exploration and early exploitation of the Upper
Mississippi River Basin took place during the last years of the Little Ice Age.
The
Mississippi River and its tributaries may have been utilized by prehistoric
peoples for 11,000 years or more - first as hunter gatherers and more recently
as agriculturists who supplemented their cultivated produce with fish, game,
and wild plants from the river, its valley, and the uplands.
The
Mississippi and its tributaries became transportation routes, facilitating the
trading of copper from Michigan, lead ore from Illinois and Iowa, obsidian from
the Yellowstone, and shells from the sea.
There were extensive trade networks in place on the Mississippi River
long before the American-European invasion.
The rivers were also avenues for the diffusion of cultural influences
long distances from their points of origin.
On the
Illinois side of the Mississippi River within sight of the soaring Gateway Arch
at St. Louis, lie the archaeological remains of the central section of an
ancient Indian city that today is known as Cahokia. Cahokia was the center of the most sophisticated pre-historic
Indian civilization north of the Rio Grande, and it acted as an intense
cultural reactor that profoundly touched and influenced aboriginal groups
throughout the Mississippi Basin. The
city was first inhabited about 700 AD by prehistoric Indians of the Late
Woodland culture. Between 800 AD to
1,000 the Mississippian culture emerged, and developed an extensive
agricultural system with corn, squash, beans, and several other seed bearing
plants as principal crops. This stable
food base, supplemented by hunting, fishing, and gathering wild food plants,
enabled Cahokians to develop a highly specialized social, political, and
religious organization. At its peak,
from AD 1100 to 1200, the city covered six square miles and had a population of
about 20,000.
A gradual
decline in Cahokia's population began sometime after AD 1200, and by the 1400s
the site had been abandoned. Depletion
of resources probably contributed to the city's decline. Climate change after AD 1200 may have
adversely affected crops and wild plants and animals needed to sustain a large
population. Agriculturists were
probably more sensitive to minor climatic changes than were hunters. Other factors such as war, disease, social
unrest, and declining political and economic power may have taken their toll.
By 1,000 AD,
American Indians were cultivating localized portions of the Mississippi River
valley below the Twin Cities for maize or corn, beans, squash, sunflowers, and
tobacco. Timbered areas in the rich
river bottoms were cleared for garden plots.
Hunting and fishing remained important, however. Farther north, in the Headwaters area, wild
rice was substituted for corn as the staple vegetative food.
During the
past 1,000 years the climate has changed several times alternating from
warm/moist (1000-1250 AD), to warm/dry (1250-1450 AD). Warm/moist conditions recurred for about 100
years, and were followed by the much cooler/moist conditions of the Little Ice
Age that lasted from 1350 to 1870 AD.
THE MYTH OF
THE ECOLOGICALLY BENIGN NATIVE AMERICAN
A popular
misconception is that American Indians were ecologically invisible, living in
perfect harmony with the environment.
On the contrary, many Indians were farmers. By 1500 AD they had cleared large areas to produce corn, beans, squash,
tobacco, and other crops. Today, 60
percent of the dollar value of U.S. crops comes from crops first cultivated by
American Indians.
Vast areas of
the Mississippi Basin were cultural landscapes where Indians regularly set
fires to improve game habitat, facilitate travel, reduce insect pests, remove
cover for potential enemies, enhance conditions for berries, and drive
game. Frequent, low intensity fires
shaped the famous oak savannas of the Midwest.
They existed as components of the landscape prior to Indian
intervention, but Indians' actions greatly expanded the extent of such
habitats.
For native
Americans, fire was a prime horticultural tool. It was easily and quickly employed, and it could be used to work
large areas. Applied periodically for
centuries, fire was a force as profound as weather in its ecological
impact. Most Indian fires were set in
spring and fall when soil moisture was high and conditions were favorable for
low-intensity burning of the forest.
This tended to create plant communities adapted to low-intensity fires
and to reduce the number of high-intensity fires caused by lightning.
The European
perception that indigenous people had small ecological impact was influenced by
the devastating effect of Old World diseases on native populations. Smallpox, introduced in the early 1500s, was
especially lethal. It has been
estimated that North America's Indian population collapsed from perhaps 18 million
in 1500 to less than 1 million by the late 1700s, when the first waves of American-European
settlers poured westward over the Appalachians. Thus, many Indian agricultural lands had two to three centuries
to reforest before the first permanent European-American settlers arrived. The landscape looked more
"pristine" than it had in more than 1,000 years.
VEGETATION
AND WILDLIFE AT THE TIME OF AMERICAN-EUROPEAN SETTLEMENT
The
Headwaters pineries extended southward to about Brainerd, Minnesota. There the Mississippi River entered an area
characterized by a mosaic of prairie, savanna (grassland interspersed with
fire-resistant trees), and extensive stands of "big woods." Although the prairie was mainly a product of
climate, much of it owed its existence to grazing and prairie fires that kept
invading forests in check. Trees
standing in prairies were prime targets for lightning that often ignited them
and/or the dry grasslands. Fires also
set by native Americans, either accidentally or purposely for a variety of
reasons including making the grasslands more attractive to grazers like elk and
bison.
Indian use of
fire as a game management tool in the Winona, Minnesota, area was documented by
Lafayette Bunnel (1897, p225).
"After a very cold spell until late in the fall, that had closed
Lake Pepin, there came several days of mild, dry weather, and then a sudden
change and a strong westerly wind. In a
few hours time it was almost as dark as night.
All of the men folks were away but myself, and I had just returned, when
Matilda told me that she did not know what to do with Mrs. Kennedy, for the
coming darkness and smoke had led her to believe that the world was coming to
an end sure enough. Just then an old
squaw with some of her people came up to the house, and asked what was the
matter, and Mrs. Kennedy told her.
Indians do not swear, but they have strong expressions of contempt, and
the Sioux woman withheld none of her language, and ended her harangue by saying:
'Thou foolish white woman, canst thou not smell the burning grass of our
buffalo prairies? Thinkest thou that
our people are fools not to prepare early food for them?'"
Along the
river corridor south of St. Paul, easily burned areas tended to be grassland or
savanna. These included bluff tops,
broad terraces, broad valley floors, and large islands. Most steep southwest-facing slopes existed
as "goat prairies." Hardwood
forests were most prevalent in areas protected from fire. These included deep valleys, north-facing
slopes, and smaller islands.
In
mid-September, 1805, after journeying upstream through the Unglaciated Area
below Lake Pepin, Zebulon Pike penned this vivid, concise description of karst
topography, savanna, and a braided river.
(Being braided is characteristic of rivers that are overloaded with
sediment.) "In this division of
the Mississippi the shores are more than three-fourths prairie on both sides,
or, more properly speaking, bald hills which, instead of running parallel with
the river, form a continual succession of high perpendicular cliffs and low
valleys; they appear to head on the river, and traverse the country in an
angular direction. Those hills and
valleys give rise to some of the most sublime and romantic views I ever saw. But this irregular scenery is sometimes
interrupted by a wide and extended plain which brings to mind the verdant lawn
of civilized life, and would almost induce the traveler to imagine himself in
the center of a highly cultivated plantation.
The timber in this division is generally birch, elm, and cottonwood; all
the cliffs being bordered by cedar. The
navigation unto Iowa River [Upper Iowa River] is good, but thence to the
Sauteaux River [Chippewa River] is very much obstructed by islands; in some places
the Mississippi is uncommonly wide, and divided into many small channels which
from the cliffs appear like so many distinct rivers, winding in a parallel
course through the the same immense valley.
But there are few sand-bars in those narrow channels; the soil being
rich, the water cuts through it with facility" (Coues, 1965, p 306).
George Catlin
also described the unspoiled Mississippi River blufflands in 1824. "The whole face of the country is
covered with a luxuriant growth of grass, whether there is timber or not; and
the magnificent bluffs, studding the sides of the river, and rising in the
forms of immense cones, domes, and ramparts, give peculiar pleasure, from the
deep and soft green in which they are clad up their broad sides, and to their
extreme tops, with a carpet of grass, with spots and clusters of timber of a
deeper green; and apparently in many places, arranged in orchards and
pleasure-grounds by the hands of art."
Stephen Long,
in his journals of 1817 and 1823, also described the prairies, savannas, and
forests along the Mississippi River between St. Louis and the Falls of St.
Anthony. His descriptions corroborate
those of Pike and Catlin.
Today, the
prairie heritage of the Upper Mississippi Basin is reflected in the names of
its cities and towns - Mound Prairie, Long Prairie, Belle Prairie, Belle Plain,
Plainview, Eden Prairie, Prairie de la Crosse (La Crosse), Prairie du Chien,
and Blooming Prairie to name a few. If
not named for the prairies, towns were often named for groves of trees that
provided shelter, fuel, and building material for pioneers - Walnut Grove,
Soldier's Grove, Maple Grove, Cedar Grove, Cherry Grove, Inver Grove, and
Spring Grove.
SETTING THE
STAGE FOR THE CAUCASIAN INVASION
Hernando De
Soto, searching for riches with 600 Spanish conquistadors, is credited with the
"discovery" of the Mississippi near Memphis in 1541. Most likely, the river came as no surprise
to him because it had appeared on a Spanish map in 1513, probably as a result of
intelligence gained from Indians. After
De Soto, 132 years passed before Caucasians again visited the Mississippi.
By the
seventeenth century, three "superpowers"- England, France, and Spain-
were competing to establish colonies and control the New World. They also hoped to discover a river that
flowed into the Pacific Ocean, so they could establish a lucrative trade route
to the Orient. The French were first to
penetrate the Upper Mississippi Valley, when, in 1673, the fur trader Louis
Joliet and his party, which included Father James Marquette, canoed from the
Green Bay of Lake Michigan up the Fox River, portaged over the low continental
divide into the headwaters of the Wisconsin River, and continued downstream
into the Mississippi. After floating
southward to the mouth of the Arkansas River Joliet concluded that the
Mississippi flowed into the Gulf of Mexico and not the Pacific Ocean. They returned by going up the Illinois
River, over the low continental divide, and down the Chicago River into Lake
Michigan.
Although they
had not found a short cut to the Orient, the exploration of Joliet and
Marquette helped establish France's claim to the interior of the
continent. Soon France was sending
colonists to populate the vast new
territory it
called "Louisiana." Other
French explorers ascended the Mississippi from its mouth; some reached its
headwaters by traveling overland from Lake Superior. A trade route became firmly established from Lake Superior up the
St. Louis River, and then overland to the headwaters of the Mississippi. A route from the Mississippi to the far
north was established by ascending the Minnesota River to its source on the
western border of Minnesota, through Big Stone Lake and Lake Traverse into the
headwaters of the Red River of the North, which flows northward toward Hudson
Bay.
La Salle was
the first European to travel the length of the Mississippi River from the Great
Lakes to the Gulf of Mexico. He claimed
the entire drainage area for France and named it Louisiana.
The French
established trading posts at many locations along the Mississippi and
demonstrated that it was navigable along its entire course. By the middle of the 18th century, France
had established trading posts throughout the mid-continent, providing further
support for ownership. St. Genevieve,
Missouri, the first permanent settlement west of the Mississippi, was founded
in 1735. St. Louis, located
strategically at the confluence of the Mississippi and Missouri Rivers, was
founded in 1764. The names of other
towns along the Upper Mississippi are further testament to the far-reaching
influence of the French: Cape Girardeau, Prairie du Chien, La Crescent, La
Crosse, Trempealeau, Lamoille, and Belle Prairie to name a few.
In 1763,
following its defeat by the British in the French and Indian War, France ceded
its holdings west of the Mississippi to Spain and its lands east of the river
to England. At the end of the American
Revolution, just 20 years later, Great Britain ceded all land from the
Appalachian Mountains to the Mississippi River to her former colony - and American settlers poured over the
Allegheny Mountains into the eastern part of the Mississippi basin.
Subsequently,
the Spanish returned ownership of the territory of Louisiana to the French,
who, in turn, sold it to the United States in 1803. Except for a very small portion of what is now southern Alberta
and Saskatchewan, Americans now controlled all of the land drained by the
Mississippi River and its tributaries.
Three
centuries passed between the discovery of the mouth of the Mississippi in the
Gulf of Mexico and the location of its source in the wilds of northern
Minnesota. Many explorers searched for
the river's source. Zebulon Pike made
the first unsuccessful attempt in 1805.
Henry Rowe Schoolcraft, guided by an Ojibwe Indian, finally
"discovered" that Lake Itasca was the true source of the Mississippi
in 1832.
With
Lieutenant Zebulon Pike's exploratory voyage up the Mississippi from St. Louis
in 1805, the U.S. Army Corps of Engineers began extensive surveys of the Upper
Mississippi. From 1817 to 1823, Major
Stephen H. Long explored the UMR, looking for ways to improve it for settlement
and commerce. As a result of his report
recommending, among other things, that canals be constructed around the rapids,
Congress assigned responsibility to the Corps for managing the Mississippi and
improving it for steamboats. The
authority has rested there ever since (Madison 1985).
PRESETTLEMENT
PLANT COMMUNITIES
An
interesting mix of modern technologies has corroborated the vivid descriptions
of presettlement landscapes by explorers Like Pike, Catlin, and Long. In 1785, the U. S. General Land Office (GLO)
initiated the Rectangular Survey System to dispense land to settlers in western
territories. It divided the landscape
into townships containing 36 sections, each of
which was one square mile in size.
At each section corner and midway between section corners, GLO surveyors
pounded a steel post into the ground.
In timbered areas they referenced the post's location by selecting two
nearby trees, and recording the direction and distance to them, the trees'
common names, and their diameter breast high.
If no trees were present, the post was set into an earthen mound and
prairie was recorded in the field notes.
After each surveyed mile, the surveyors recorded type of terrain, soil,
plants composing the undergrowth, and tree species. Early surveyors and explorers often used the term "oak
opening" for savanna.
As part of
the U. S. Geological Survey's Upper Mississippi River Long Term Resource
Monitoring Program, survey records of the GLO have been used to reconstruct the
structure and distribution patterns of plant communities that existed over 150
years ago along the UMR. Using
digitized GLO data, computer-generated maps plot the former forests, savannas,
prairies, marshes, and areas of open water.
These
reconstructions reveal that prairies once dominated the floodplain. Forests were generally restricted to
islands, banks of the Mississippi and its tributaries, valley slopes and
ravines. Flooding has long been
considered the principal factor influencing plant community types on the
floodplain, but it is now known that fire, either natural or human-caused,
played an important role in maintaining floodplain prairies, savannas, and open
woodlands.
In the Pool 4
area, for example, GLO surveyors reported that island forests were dominated by
flood tolerant species like elm, silver maple, willow, bur oak, birch, and
ash. Because the GLO surveyors did most
of their work along the Mississippi during the winter when trees were leafless,
they may not have always distinguished bur oak from swamp white oak. The barks of the two species are similar.
Uplands were predominantly covered with savanna communities of fire-tolerant
white oak, bur oak, and black oak. Some
of the savannas had a park-like distribution of trees with a grassy understory. In others, oak groves were interspersed with
open prairies and dense thickets of fire-stunted oak and hazel brush. Fire-sensitive sugar maple - basswood
forests were restricted to steep mesic ravines and north facing slopes
protected from fire. The floodplain had
communities similar to both islands and the surrounding uplands. Bur oak, tolerant of both fires and floods,
was the dominant tree species on both floodplains and uplands in 1848. Presently, silver maple is the dominant
flood plain species in Pool 4.
Farther south, using GLO survey records from 1815-1817, reconstructions were made of the presettlement landscape at the confluence of the Illinois and Mississippi Rivers. About 56% of the floodplain consisted of forest and savanna dominated by hackberry, pecan, elm, willow, and cottonwood.