TTwowo RRiversivers FFlowinglowing RRecente c e n t AArchaeologyr c h a e o l o g y iinn DDowntowno w n t o w n DDese s MMoines,o i n e s , IIowao w a Reverse L-shape outlines offi cial boundary of 13PK61 (Fort Des Moines No. 2) (City of Des Moines) Two Rivers Converge n 1843, a military post, Fort Des Moines No. 2, was established on a terrace above I the confl uence of the Raccoon and Des Moines Rivers. Th is fort, and the early town that developed from it, would eventually become Iowa’s modern capital city, Des Moines. Since those early days, the urban area south of the Court Avenue District has undergone rapid change and the original land surface of the fort and early town was buried. Archaeological investigations beginning in the 1980’s had uncovered artifacts and features revealing the location of one of the fort’s structures. Yet the location and layout of the rest of the short-lived post remained unclear. In addition, other recovered data indicated this was not the fi rst time humans had occupied “the Point.” Th e site had been used by Native American Indian groups at diff erent times over thousands of years. Designated as 13PK61 (Fort Des Moines No. 2) by the University of Iowa’s Offi ce of the State Archaeologist, the site was found eligible for inclusion in the National Register of Historic Places in 1989. As the year 2000 approached, planned redevelopment projects in this oldest section of the city were being (Library of Congress) realized. As ground was cleared for the Martin Luther King Jr. Parkway extension, the Vine Street Lofts, and the new Science Center of Iowa, a combination of federal requirements and agreements by government and business groups led to another series of archaeological excavations in the aff ected area. Archaeologists would once again probe a buried land surface for clues to the City of Des Moines’ past. Th is unique opportunity to increase our knowledge of the city’s history, and its prehistory, was greeted with great interest by the citizens of Iowa. Th e two rivers of the past and the present were about to meet again. (USGS) 1 The Land Before eologists have defi ned the diff erent it came to a standstill, the northern portion of the landform regions of Iowa based on the metro area was covered by a glacier several hundred G earth-shaping processes that formed them feet high. Th e Raccoon River formed as meltwater and the time period in which they occurred. Periods fl owed along the glacier’s southern margin. Soil and of glaciation in which the action of ice shaped the rock deposited along this margin formed the ridges land have played an important role in creating many and hummocky terrain of the Bemis Moraine. Iowa’s of these landforms. Capitol Building sits on part of this end moraine. Initially, meltwater drained from within the glacier Th e City of Des Moines lies along the boundary by way of the old Beaver Creek channel that fl owed of two of these glacially-sculpted regions, the between Capitol Hill and Four Mile Ridge. As the more recent Des Moines Lobe and the older ice began to retreat, the Des Moines River valley Southern Iowa Drift Plain. Its location marks the north of the present-day city was formed from southernmost extent reached by glaciers during the meltwater fl owing in a channel beneath the ice. most recent ice age, the Wisconsinan. About 14,000 Th is became an exposed outwash channel as the ice years ago, a fi nger of ice, the Des Moines Lobe, receded further north that cut off Beaver Creek, surged into Iowa from the main ice sheet that lay diverting the fl ow to its present channel west of the across North and South Dakota and Minnesota. As Capitol. As it met the Raccoon River, the Point at the confl uence of the two rivers began to be formed. As the ice continued to release its grip on the land, Northwest Paleozoic Iowa Plains Plateau erosion deepened valleys. Wind-blown soil and Iowan Surface Des Moines Lobe Des Moines Lobe Southern Iowa Missouri Drift Plain Alluvial Plain Loess Hills Southern Iowa Mississippi Polk County Drift Plain Alluvial Plain Glacial processes played an important role in the formation of much of Iowa’s landscape. Th e diff erent landform regions formed at diff erent times City of Des Moines and have unique characteristics. Southern Iowa Drift Plain Th e City of Des Moines is sited on the boundary of two of these landform regions 2 episodes of fl ooding built up elevated areas called Allied offi cials recognized the signifi cance of this terraces in the low-lying river bottoms. Conversely, discovery and, after contacting the State Historical other landscape features called benches were Society of Iowa, eventually donated the bones of this formed as fl owing water cut into alluvial deposits. largest of Ice Age mammals to the museum. High enough above the rivers’ fl ood plains, these landforms invited human occupation. Th e Point is An excellent Ice Age exhibit, “Mammoth: Witness one such place. Archaeologists have benefi ted from to Change” at the State Historical Building in Des studying such land-forming processes and can better Moines’ East Village features some of these bones predict locations of promising sites as a result. as well as the cast of another mammoth skeleton discovered in Wisconsin. Also on display are many ome 12,500 years later, on August 14, 2001, related interpretive exhibits that more fully explain construction workers were boring holes with the geological events and natural processes that led S a giant auger in downtown Des Moines. to the formation of the present Iowa landscape. Th ey were preparing holes for support columns for the new Allied Insurance and Farmland Insurance parking ramp at 11th and Walnut Streets. As the auger struck bedrock, 55 feet below the surface, it cut through the skeleton of a woolly mammoth lying on the former valley fl oor of the Raccoon River. Des Moines RiverHighland Park Former BeaverFour Mile Ridge Creek Cha nnel Uplands Capitol Hill Raccoon River Visit “Mammoth:Witness to Change” online at: Highlighted are some of the key glacial features http://www.iowahistory.org/museum/exhibits/mammoth/index.htm within the City of Des Moines. 3 The First Settlers nto this renewed landscape Paleo-Indian Archaic Native American Indian groups I 11,000 B.C. - 8,500 B.C. 8,500 B.C. - 800 B.C. migrated and interacted with the environment. Archaeologists have Early Early 11,000 B.C. - 9,000 B.C. 8,500 B.C. - 5,500 B.C. identifi ed distinct Native American Middle cultural periods that have occurred in 5,500 B.C. - 3,000 B.C. Central Iowa and the Upper Midwest Late Late spanning thousands of years. Some of 9,000 B.C. - 8,500 B.C. 3,000 B.C. - 800 B.C. these periods have been subdivided into Recent discoveries have A period of rapid phases to refl ect distinctive approaches to resulted in diff ering climatic and opinions on where the environmental change life within that period. Paleo-Indians migrated from Hunter-gatherers sought smaller game Small groups of mobile hunters Increased use of plant foods Hunted large game such as woolly mammoth, Early semi-permanent mastodons, and settlements giant bison Diff erent phases have Sites identifi ed by characteristic projectile distinctive spear point point styles types, e.g. Clovis and Folsom 4 Woodland Late Prehistoric Oneota Historic 800 B.C. - A.D. 1200 A.D. 900 - A.D. 1200 A.D. 1250 - A.D. 1673 A.D. 1673 - Present Early 800 B.C. - 200 B.C. Middle 200 B.C. - A.D. 300 Late 300 A.D. - A.D. 1200 Introduction, Incudes Great Oasis, Large permanent and Tribes struggle to development and Mill Creek, Glenwood semi-permanent villages maintain cultural use of pottery cultural groups identity as pressure Large scale agriculture from Euroamerican Increased agriculture Mixed economy with cultivation of settlers mounts of hunting and beans, squash, and corn Construction of burial gathering and intensive Native life ways and mounds, interaction horticulture Shell tempered ceramics arts decline as European with the great mound were thinner and manufactured goods building cultures of the Increased use of bison stronger become more common Ohio and Mississippi for food and raw River valleys materials Large pits used for Villages and whole tribes storage of food and other moved often due to Bow and arrow Greater complexity items territorial pressures introduced in social and political organizations Ancestors of Ioway, Rivalry between tribes Larger populations Otoe, Winnebago, increases as they compete Distinctive ceramic Missouria, and other for resources and Trade networks traditions Midwestern groups that territory continued into Historic Long-distance trade period Euroamerican diseases networks contribute to declining Indian population 5 Tribes On The Move n the brief period from 1650 to 1673, Th e culturally and linguistically related Sauk and European colonists began to learn of Iowa’s Meskwaki faced mounting pressure themselves from I Indian tribes through other tribes they colonists and settlers, fi rst from the French in the were already in contact with. In turn, the Iowa early 1700’s, and then in confl ict with the Americans tribes were introduced to European trade goods during the Black Hawk War. Th eir defeat resulted and diseases through these same intermediaries. in the treaty called the Black Hawk Purchase in In 1673, two canoes carrying the French explorers 1832 in which they relinquished their land along Father Jacques Marquette, Louis Joliet, and fi ve the eastern border of Iowa.