Polk County Conservation

Iowa Archaeology

Grinding Stone

The Des Moines River valley is rich with Native American history. Archeology sites have been found in Central Iowa that indicate the Archaic, Woodland, and Oneota period cultures inhabited this area from 7,500 BC to 1650 AD.

During the Archaic period (7,500 – 500 BC) environmental change occurred rapidly. Archaic peoples flourished in Iowa hunting bison, deer, elk, smaller animals, and gathering many types of plants.

The Woodland period (500 BC – 1,000 AD) saw major technological, economic, and social developments. The use of pottery, bow and arrow, plant domestication and cultivation, and burial mound construction became widespread.

The Late Prehistoric period (1000-1650 AD) is divided into several cultures including the Oneota and Great Oasis cultures who lived in the Des Moines River Valley in central Iowa.  During this time, these cultures practiced a mixed economy of hunting and gathering and intensive horticulture. Crops included corn, beans, squash, sunflowers, tobacco, and a variety of native species.

Learn more about the Native American artifacts that have been found in Yellow Banks Park.


The Office of the State Archaeologist - The mission of the Office of the State Archaeologist is to develop, disseminate, and preserve knowledge of Iowa's human past through Midwestern and Plains archaeological research, scientific discovery, public stewardship, service, and education.

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Administration Office
12130 NW 128th St
Granger, IA 50109

P: (515) 323-5300
F: (515) 323-5354

Monday – Friday, 8:00 a.m. – 4:30 p.m.

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