The Paleo-Indian period in North America dates to
about 9,500-7,500 B.C. Paleo-Indians in Iowa encountered
vastly different environments than those of the recent past.
The climate was cooler and wetter than present averages. In
north central Iowa, Paleo-Indians lived in recently
deglaciated landscapes covered by boreal and
conifer-hardwood forests, shifting through time to elm- and
oak- dominated woodlands. Woodlands predominated in most of
the state as well, and prairie, if present, was very
The Clovis complex is the earliest well defined
archaeological culture currently known in North America.
Clovis and other fluted projectile point styles were made
during the first two-thirds of the Paleo-Indian period, and
Dalton and unfluted point forms date to the latter one-third
of the period. Aside from these lanceolate (lance-shaped)
points, defining characteristics of the Paleo-Indian period
include distinctive butchering tools, extensive use of
exotic chert types, and specialized lithic technologies.
Fluted and unfluted point forms have been recovered as
surface finds from upland and valley locations throughout
peoples were extremely mobile, hunting various animals
including now-extinct large mammals such as mammoth,
mastodon, and giant bison. Most Paleo-Indian sites so far
located in the United States are large mammal kill sites,
and little is known of other site types. No Paleo-Indian
base camps have yet been documented in Iowa. To date, the
best documented fluted point site in Iowa is a
plow-disturbed cache of Clovis points known as the
Rummells-Maske site in Cedar County.
The Early Archaic period (7,500-5,500 B.C.) is viewed
as a somewhat transitional period between cultures relying
on big game for subsistence and those with a more rounded
forager adaptation. Environments changed relatively quickly,
as deciduous woodlands, mixed with prairies in western
areas, became established over most of the state.
Populations probably depended on bison in western Iowa and
on deer and elk in eastern Iowa. These large mammals were
supplemented by smaller game and by increasing use of plant
foods. Settlement types included somewhat permanent base
camps and seasonally occupied resource procurement camps.
Excavated sites, such as the Cherokee Sewer site, suggest
local populations were small and that they were tied to a
seasonal round of resource exploitation. Representative
artifacts include medium to large spear points, often with
serrated and beveled blade edges.
The Middle Archaic period (5,500-2,500 B.C.) is so
poorly known in Iowa that it has normally been lumped with
the Early Archaic. Cultural adaptations may have been
similar, but environmental conditions became increasingly
arid throughout the period. The Middle Archaic period
corresponds to the warmest and driest postglacial period,
commonly referred to as the Atlantic episode, or the
Hypsithermal. Human populations throughout the Midwest
gravitated to the wetter river valleys, and because of this,
Middle Archaic sites are often deeply buried and difficult
to locate. During the Hypsithermal, great masses of silt
filled river valleys, and alluvial fan development was
rapid. Many Middle Archaic sites are buried in these
By the Late Archaic period (2,500-500 B.C.) the
Midwest was becoming a fairly crowded place with the
incidence of intergroup encounter rising sharply. This
situation resulted in similar subsistence strategies over
broad areas, but also in increased territoriality, local
differentiation in artifact styles, and development of
intergroup trading networks. The end of the dry Hypsithermal
resulted in increased stability of the resource base and
made many previously unsuitable areas attractive for
settlement. Population levels appear to have increased
substantially, and a somewhat sedentary life way as well as
construction of large ossuaries (multiple-interment
cemeteries) are documented for this period. The use of
communal cemeteries reinforces the interpretation that
populations were becoming more sedentary.
The Woodland tradition (500 B.C.-A.D. 1000) was
characterized by improved technologies, such as ceramic
production and horticulture, leading to an overall increase
in productive efficiency, and by the construction of burial
mounds. Although these characteristics originated during the
Archaic, only after 500 B.C. did they come together and
become adopted over a wide area.
Woodland peoples refined their hunter-gatherer adaptations,
making heavy use of fish and clams in major river valleys,
and continuing to exploit deer and bison. Dependence on
cultivated plants increased. Native plants often thought of
as weeds today were grown for their nutritious seeds.
Woodland farmers developed domesticated varieties of some of
these native grain crops long before corn or beans became
important. Climatic conditions approached modern averages,
landform development stabilized in most places except in
flood plains and stream channels, and vegetation patterns
were much like the forest-prairie mix documented by
nineteenth-century land surveys.
Early Woodland settlements (500-100 B.C.) in
the Midwest were small and seasonally occupied. Early
Woodland subsistence patterns in Iowa are not well known,
but they probably involved broad-based procurement of
mammals, birds, and aquatic species. Early Woodland peoples
built large burial mounds similar to some in Ohio, and they
interacted with groups throughout the Midwest, as evidenced
by artifacts made of exotic raw materials. The typical Early
Woodland spear point was a straight stemmed or contracting
stemmed point, and pottery of the period includes both a
thick, flat- bottomed type (500-300 B.C.) and a thinner,
bag-shaped type often decorated with incised lines in
geometric patterns (300-100 B.C.). Early Woodland sites are
relatively common in the Mississippi Valley but are
difficult to identify in central and western Iowa. Perhaps
groups on the eastern Great Plains retained an Archaic
lifestyle during this period.
The Middle Woodland period (100 B.C.-A.D. 300) is
noted for its refined artworks, complex mortuary program,
and extensive trade networks. Middle Woodland communities
throughout the Midwest were linked by a network
archaeologists refer to as the Hopewell Interaction Sphere.
Trading involved materials such as Knife River flint from
North Dakota and obsidian from the Yellowstone Park area.
Also exchanged through the Hopewell network were artifacts
of marine shell, copper, mica, and several pipestones, as
well as high quality ceramic vessels and possibly perishable
materials which have not survived archaeologically.
By Late Woodland times (A.D. 300-1000) the
continent-wide exchange of exotic goods declined but
interaction between communities and tribes continued.
Population levels apparently increased rapidly. In some
parts of Iowa, Late Woodland peoples aggregated into large,
planned villages, but in most of the state settlements
continued to be small and generally became more dispersed
across the landscape. Uplands and small interior valleys
became settled or more heavily utilized. Late Woodland
peoples introduced the bow and arrow into the Midwest.
Continued native crop horticulture and diversified hunting
and gathering provided the subsistence base through most of
the period. Corn was introduced to many groups after around
A.D. 800 but did not form a staple crop until the Late
During the Late Prehistoric period the Oneota culture
dominated much of eastern Iowa as well as extensive parts of
central and northwestern Iowa. Oneota peoples lived
throughout the Midwest between around A.D. 1050 and 1700.
The Plains Village pattern appeared in Late