Plum Island Site


The Plum Island Site is located in the Illinois River near Starved Rock, LaSalle County, Illinois, in the vicinity of the Hotel Plaza site and the Zimmerman site. It is a multi-component site representing Prehistoric, Protohistoric and early Historic periods, with the main occupation being a late Prehistoric to early Historic component with Upper Mississippian affiliation.

History of Archaeological Investigations

Excavations took place in 1930 under the auspices of the University of Illinois. A total of 7,316 artifacts was collected, but the site report was not done until 1964 when Gloria Fenner of the University of Illinois did a Masters Thesis and followed it up with an article in the Illinois Archaeological Survey Bulletin. Unfortunately in the interim many of the artifacts were misplaced and some stratigraphic information was lost.

Results of Data Analysis

Excavations at the site yielded Prehistoric and Historic artifacts, pit features, burials, animal bone and plant remains.

Components

Several Prehistoric and Historic components were identified at the site:
There were no house structures noted at the site. However, the entire site was honeycombed with pit features, totaling 470, some of them overlapping. Three types were recognized: refuse pits, firepits and “unidentified” or uncategorized. Eight burials were also excavated, with 4 of them having grave goods.
The refuse pits were thought to have first been storage pits that were converted into refuse pits once their contents began to sour. They contained animal bone, charcoal and artifacts.
The firepits appear to correspond to what has ethnographically been described as “macoupin roasting pits” by the early French explorers Deliette and LaSalle and described from the Zimmerman site. The macoupins are apparently tubers from a species of water lily, perhaps the American Lotus. Tubers of Nelumbo lutea have been recovered from similar roasting pits at the Elam and Schwerdt sites on the Kalamazoo River in western Michigan; and tubers of the white water lily have been recovered from roasting pits at the Griesmer site in northwestern Indiana. This particular cooking technique may have been used prehistorically for several species of similar water lillies, or other similar root plants. No tubers were specifically recovered from the Plum Island site, however. This may be due to the fact that there was no systematic effort by the excavators to collect plant remains.

Animal Remains

Remains from a wide variety of species were recovered from the site. The main species present were fish, deer, elk, raccoon, beaver, dog, turtle, snails and fresh water mussels. In addition, bison, mink and bobcat were recovered in smaller amounts. These remains were not modified into tools like the bone tools described in the Artifacts section below, and may be considered food remains or, in the case of the dog, the remains of ceremonial activities. Dog sacrifice and dog meat consumption was observed to have ceremonial and religious implications in early Native American tribes.

Plant Remains

Plant remains were not systematically collected via the flotation technique as that did not become standard archaeological practice until the 1970s. The excavators did however recover maize in the form of kernels and corncobs. The maize was an earlier type than that found at the Zimmerman site.

Artifacts

Pottery Artifacts

Archaeologists often find pottery to be a very useful tool in analyzing a prehistoric culture. It is usually very plentiful at a site and the details of manufacture and decoration are very sensitive indicators of time, space and culture.
No whole or completely reconstructable vessels were found at the site. Therefore, the researchers looked primarily at rim sherds and distinctive body sherds to analyze the pottery.
Early Occupations
The Early and Middle Woodland periods are represented by a small scattering of pottery at Plum Island. The Early Woodland is represented by Marion Thick, the first pottery ever made in this part of North America, and traces of a few other early types. The Middle Woodland is represented by Havana Ware and Naples Ware, among others. The Havana Culture was thought to be a local variant of the more prominent Middle Woodland cultures such as the Adena and Hopewell cultures of the Mississippi and Ohio River Valleys. Middle Woodland cultures are characterized by their large burial mounds, some of which are still visible today; as well as their distinctive pottery forms, ceremonial practices, agricultural activities, and widespread trade networks.
Upper Mississippian Component
A total of 6,989 sherds were collected from the site, of which 6,838 were assigned to the Upper Mississippian component at Plum Island.
Two types of pottery were found within this component; shell tempered Fisher ware and grit-tempered Langford ware.
Fisher Ware was first described at the Fisher Mound site in northeastern Illinois near the mouth of the Illinois River. It has also been noted at the Anker and Hoxie Farm sites near Chicago, Illinois.
This pottery is characterized by shell tempered, globular vessels with cordmarked surfaces and straight to excurved rim profile. Decoration, when present, consists of trailed or incised decoration forming arches and festoons, often combined with punctates. Notched lips and rim lugs are also common.
Three types of Fisher ware were reported:
Langford Ware was also first reported at the Fisher site, and has also been found at the nearby Zimmerman and Gentleman Farm sites. It is a grit-tempered ware usually with smoothed surface. Decoration, when present, consists of incised and trailed lines, punctates and finger impressions, combined to form arches and festoons. Rim profile is excurved and sometimes collared. Lugs and loop handles are present on some vessels and nodes are also sometimes present.
The following types of Langford Ware were reported:
Non-pottery artifacts recovered from the site included:
The non-pottery artifacts found at an archaeological site can provide useful cultural context as well as a glimpse into the domestic tasks performed at a site; ceremonial or religious activities; recreational activities; and clothing or personal adornment.
Some of the most prominent and diagnostic non-pottery artifacts are presented here in more detail:
MaterialDescriptionImageQtyFunction / UseComments / Associations
Chipped StoneSmall Triangular Points 3Hunting/fishing/warfareAlso known as “arrowheads”; are thought to be arrow-tips for bows-and-arrows. The usage of the bow-and-arrow seems to have greatly increased after A.D. 1000, probably as a result of increased conflict.
BoneGame counter1Entertainment functionThese have been found at Fisher, Huber, Langford and Oneota sites and may have been used in a gambling game. Gambling was noted to be a popular pastime among the early Native American tribes.
BoneHarpoon1Fishing functionSimilar harpoons made of bone or antler have been recovered from other Upper Mississippian sites in the Midwest, including Fisher, Fifield and Oak Forest.
BoneBeamer1Domestic function / de-hairing hidesCommonly found at Upper Mississippian sites in northern Illinois

Significance

The Plum Island site reflects a series of occupations going back thousands of years, but the main occupation consists of a late Prehistoric Upper Mississippian component. This component apparently lasts until the Protohistoric or early Historic period based on the European trade goods present at the site.
No house structures were present at the site, but the presence of numerous pit features indicates intensive occupation took place, possibly to harvest and roast plants like macoupins in the fire pits. Very little bison bone was found in the food remains, possibly because bison were not present until after A.D. 1600 in most of Illinois.
The trait list of Plum Island was compared to that of other sites in Illinois to gauge regional relationships in material culture. It was found that Plum Island shared 79% of traits with the Heally Component at the Zimmerman Site; 75% with the Fisher Period B; and 67% with the Gentleman Farm site. The trait lists combined all attributes including pottery, other artifacts, features, plant remains and animal remains.