9UNP0434SD_Kent_Dickerson

- Paul Rogovitch: Good afternoon. Welcome to another session of History Sandwiched In, this May being, of course, archaeology month. We have another topic in archaeology. The museum has its own archaeology program called, of course, the Museum Archaeology Program. And today we have the field coordinator to talk about some of the work that he's been doing over the past few years. So please welcome Kent Dickerson to History Sandwiched In. 
(applause)

- Kent Dickerson: I've got a little stool here so I can save my knees some wear and tear. I've got a prepared text that I'll be referring to, but certainly, if you have any questions just fire 'em away. 

I'd much rather give you the information you want than what I thought you would want. And there's also a tendency amongst us to talk in these jargon terms that we forget that everybody else doesn't use in their everyday life. If you don't understand, just ask. Between 1992 and 2002, the museum archaeology program of the Wisconsin Historical Society conducted a series of archaeological investigations on behalf of the Wisconsin Department of Transportation of the proposed realignment of state highway 110 in Winnebago County. The project extended 7.5 miles from highway 41 northwest to county highway G along the northeast shore of Lake Butte des Morts. The investigations resulted in the identification of 42 archaeological sites. These sites contained evidence of occupation associated with the late Paleoindian, middle- and late-archaic, early-, middle-, late-woodland, Oneota, and historic Eur-American traditions. 27 of the sites were considered potentially eligible for the National Register of Historic Places, and additional investigation was recommended. The selection by WisDOT of corridor G and the refinement of the area of potential effect avoided all but nine of the sites. One of the nine sites was the Skeleton Bridge site. 

This is a pre-contact Native American site in east-central Wisconsin. It's located on a ridge east of Daggett's Creek. The site was originally identified and investigated by Stephen Bedwell of the University of Wisconsin-Oshkosh over a weekend in 1971. Bedwell and his students conducted test excavations at the site for an introductory archaeology class. However, Bedwell tragically died in a boating accident on Lake Winnebago in 1972 before the data could be completely analyzed and written up. The Lake Butte des Morts area has seen extensive archaeological research and investigation, which has resulted in the identification of 69 sites within two miles of the Skeleton Bridge site. The Skeleton Bridge is kind of lost in there a little bit, but it's located right in the middle. The area surrounding the Skeleton Bridge site was the locus for extensive pre-contact Native American occupation. The site appears to be part of a larger complex of sites concentrated along the lakeshore in the village of Butte des Morts and along the outlet of Daggett's Creek. Individual site boundaries have been defined based upon topography and in some cases modern artificial boundaries, such as roadways. 

The complex is likely a reflection of the frequent reuse of the entire area east of Daggett's Creek. Individual sites may at one time have been one large contiguous site or a series of related sites. The smaller sites may have been satellite sites associated with larger, more permanent sites located on the shores of Lake Butte des Morts. The Skeleton Bridge site lies on a crest of a ridge that overlooks the floodplain of Daggett's Creek. Daggett's Creek is over to the left. This is all high ground. A shallow drainage is situated along the southern boundary of the site while a seasonally inundated marsh surrounds the western tip of the site. A seasonal spring is located to the north just adjacent to the site. The site was originally confined to the woodlot during Bedwell's investigation, but it was expanded eastward into the agricultural field and covers approximately a half-acre. The location of the archaeological site was viewed as an ideal for pre-contact resource procurement and processing associated with hunting and foraging along Daggett's Creek. 

This is how the site looked when we started our investigations in 2001. The wooded area here is looking across a fairly newly-planted alfalfa field. That's looking back the other way. Did I skip one? No, okay. There's peering into the woodlot. It was fairly dense understory and we spent some time cleaning it up a little bit so we had a nice sight line throughout the site. This is from the road, from Brooks Road looking at the back of the site. You can see the marsh grasses surrounding it and then there's right at the base of the ridge so you can see how high the ridge is compared to the surrounding wetlands. We investigated the wooded portion of the site using hand-excavated 1 x 1 meter units, usually dug in pairs, so it was 1 meter x 2 meters. 

And during the excavation, we noticed, this is a little bit dark, sorry, that soil profiles were fairly consistent across the site area. A or topsoil, black to dark brown, silty, clay loam, was about 12 centimeters deep. Then there was a narrow band of transition soil, and then at the base was the underlying B or subsoil, typically a redish-brown, heavy clay, silt loam. Within the wooded portion of the site, a total of 250 1 x 1 meter units were excavated. I've just got several shots here just to give you a sense of the excavation. A lot of pictures I took, you can see early on, there were leaves. We were there in the fall during leaf drop and until it got much too cold that winter. We went back the following spring, so you'll see a little bit, sometimes people will be wearing coats, sometimes people will not be wearing coats, and the trees will have leaves. 

- Question? 

- Dickerson: Sure. 

- How deep were the excavations? 

- Dickerson: They varied somewhat, but typically about 30 to 35 centimeters. Sometimes a few units went deeper, but not very deep. That subsoil is a very heavy clay. The Native Americans obviously did not want to dig in it any more than we did. So most of the deposits were fairly shallow. One of the joys of the site, as you can see, there are lots of trees, lots of roots that we had to deal with during the excavation. Within the former agricultural field, the plow zone was mechanically stripped from about 2400 square meters within the area of potential effect. The Winnebago County highway department provided a gradeall and operator to remove the plow zone and to backfill the resulting trench once the investigation was complete. Plow zone, soils that were removed were approximately 20 centimeters below the ground surface. 

The removal of plow zone was monitored by two archaeologists who visually examined the exposed surface for indications of sub-surface cultural features and/or artifacts. So the darker area is what we stripped. I couldn't find a great picture of the heavy equipment stripping, but you can see there in the back, the gradeall at work and once it was done, there was our trench. Look at this tree here. Watch what happens to that tree a little bit later. We did identify some features in the stripped portion of the site. Not a whole lot, they were very shallow, a low concentration of artifacts was recovered there. The plowing of this portion -- plus it's further away from the creek, had pretty much had an adverse affect on the deposit. There we are excavating one of the features that we did identify. And there's that tree. 

(laughter)

 We had just moved the port-a-pot out to that location. It was back by the woodlot. Although it was closer for us to use, as you well may know, port-a-pots sometimes have unpleasant side effects. Some odor and stuff. So we moved it a little further away from us and we thought, well, it'll be easier for the guy to come and deal with it, so we had him put it there. And just right after we had put it at that location, fortunately it was over a weekend when we weren't there, a windstorm came up and took that tree out. We had no idea that it was quite as hollow as what it was. We could just imagine that if someone had been in there when that thing went down, it would have been very frightening. 

(laughter)

 The excavated sample of the site comprised about 2600 square meters or 27% of the total site area. This is towards the end of the excavation, you can see we've got it all cleaned up. Just an overview. A total of 79 cultural features were identified. The identification of a feature was based upon the distinct concentration or patterning of material culture and/or the presence of soil anomalies. Feature types included pit features, fire-cracked rock concentrations, and middens. Pit features included small to medium-sized basins, flat-bottomed pits, deep cylindrical pits, and very small, steep-sided basins. Some examples of those, again, some of these are dark, which I apologize for. You can see the dark soil extending into the subsoil. Typically we couldn't see it in the A horizon, it was only when we got down to the B horizon and the lighter-colored soil was all around, then the feature would be readily seen. 

This was out in the stripped area, a very large, just black, middens sort of deposit. There was not a whole lot in it, but just a ton of small, burned bone fragments in it. Fire-cracked rock concentrations. The Skeleton Bridge site feature assemblage is not particularly large or diverse. Although features are found across the site, the distribution is not contiguous, but displays an uneven, somewhat clustered pattern. While the majority of the features consist of small single zone pits interpreted as short-term cooking facilities, other much larger features and feature complexes indicate large-scale, time-intensive food processing activities. Functions suggested by the feature assemblage include earth ovens, hearths, refuse pits, post holes and multi-function facilities. Some features bear witness to the repeated occupation of the location through time with truncated or overlapping feature boundaries and mixed temporal artifact assemblages. The feature clusters appear to be associated with centralized hearths or ovens. The clusters may represent activities which were communal in nature, possibly involving several households and not serving merely a single function. 

Here we are at the very end of the site of the excavation. As you can see, you can see the heavy equipment in the background. We were trying to wrap things up and they were wanting to build a road. So we were out there till the bitter end, trying to get as much data as we could. They were dropping trees around us and pushing dirt around. A total of 162,938 artifacts were recovered from the Skeleton Bridge site during the 1972 to 2002 investigations. The artifact assemblage comprised of fire-cracked rock, about 50% of the artifacts recovered were fire-cracked rock and other stone or lithic artifacts. Daub, pottery, and faunal remains and a few historic artifacts made up the rest. 

- Did you say 1972? 

- Dickerson: What did I say? 

Yeah, 1972 was when Bedwell was there. Well, it was 1971. And then we finished our investigations in 2002. 

- Okay, but then you had this big push because of the road going in. 

- Dickerson: Right. The majority of the excavation was done in 2001 and 2002, but as far as the assemblages, the artifacts that we had to look at, dated back from Bedwell's investigation in 1972, we had some other artifacts that we recovered when we re-identified the site in 1992. We did a phase two evaluation in 2000. So all of those had generated small assemblages. Most of that 162,000 artifacts were recovered during 2001 and 2002 excavations. The assemblage contains diverse diagnostic artifacts, which indicated multiple occupations beginning with the late Paleoindian stage, including the late-archaic, early-woodland, middle-woodland, late-woodland, emergent-horizon and developmental-horizon Oneota, and historic Native American and Eur-American traditions. 

Based upon the artifact assemblage, the predominant occupation is associated with the late-woodland. As I said, fire-cracked rock was the most common artifact recovered from the Skeleton Bridge site. The assemblage consists of 85,330 pieces weighing almost two tons of rock. And these are some smaller pieces that they're counting out there. 24 rock types were identified, but the most common rock that was utilized was granite. Fire-cracked rock is a result of rock exposed to extreme heat and this would have occurred during a variety of functional and social activities. People gathering around stone-lined hearths to cook, eat, stay warm, converse, tell stories. Heated rock provided a means to maintain and control temperatures while roasting, baking and boiling. A typology for fire-cracked rock was used based upon the causes of breakage. Thermal fracturing of rock differed depending upon direct exposure to fire, which is referred to as "basic fractures," quenching with water to produce steam is a common fracture. 

Placing in water to produce a boil, classic fractures, and the continued reuse of fractured pieces will result eventually in pieces too small to efficiently reuse, or residual pieces. At the Skeleton Bridge site, the most common fracture pattern found was basic, or directly exposed to fire. That was predominantly in feature context while the fire-cracked rock recovered outside of the features was predominantly residual. The relatively high percentage of residual fire-cracked rock suggests an extensive occupation at the site and/or regular seasonal re-occupation. Another possible reason for the high percentage of residual fragments involves the high utilization of granite, because as you heat granite repeatedly, it breaks down more readily than compared with denser, more compact rock matrix. 

- I have a question. 

- Dickerson: Sure. 

- What is the time range of occupation? 

- Dickerson: The late Paleoindian, we're talking about approximately 8,000 years ago. The late-woodland period, when we feel that most of the artifacts date from that period, approximately 1500 to 2000 years. 

That's the distribution of fire-cracked rock. And that's not an uncommon distribution of artifacts in general from this site. Daggett's Creek is over this way. They seemed to want to be closer to the water rather than farther away. So I've got just a few other distribution maps and you'll see similar sorts of distributions. Daub. We recovered a fair amount, 2400 pieces of daub, weighing about 30 pounds. Daub was much more fragmentary. The daub is fire-hardened clay. Several larger fragments exhibit stick or twig impressions, but most were small, rounded or angular bits of fire-hardened clay. 

A quarter of the total was recovered from feature context while 75% was recovered from just the excavation units. The daub recovered from feature fill may represent the remains of a clay-lined firepit or cooking facility. It may also represent nothing more than just incidental or unintentional firing of the natural clay soils that were being exposed to heat during cooking or other activities. As for the daub recovered from unit excavation, some of it may have been raked out of the features, but it's also possible the daub may represent the remains of wattle-and-daub structures. Very few features identified as post molls or other evidence of actual structures were identified during the excavation of the Skeleton Bridge site. However, aggregates of daub, especially those bearing twig impressions, are suggestive that structures may have been present. The site contains 34,000 pieces of unmodified debitage. Debitage is the remains from chipped stone tool manufacturing. For every arrowhead or projectile point, you make a lot of debris. And so that's one of the most common artifact types that archaeologists encounter in the field. 

And we divide it between early stage and late stages. In the early stages of lithic reduction you get the larger, coarser materials, and then as the pieces refine, you get smaller, thinner flakes. So that's the distribution of early stage, that's the distribution of late stage. You can see in both cases there's a concentration here. This was obviously some sort of activity area for producing chipped stone tools. And at least 24 different lithic raw material types were identified in the debitage assemblage. The most common raw material type was Galena chert, which accounted for 91%. But Prairie de Chien chert, land chert, quartz, these were all materials that were readily used by Native Americans in Wisconsin, rounded out the assemblage along with some exotic materials that we'll talk about a little later. A total of 90 projectile points were identified in our artifact assemblage. Starting with the one on the left. 

This point shares several attributes with the agate basin point type. Agate basin is a variety of a late Paleoindian stage lance point that has a wide distribution across the midsection of North America. In Wisconsin these points are believed to represent a period roughly 8000 to 6000 BC. The next point there is a straight stem point. Short stem, broad blade, rather large, random percussion flakes. It was rather reminiscent of a point type we call "Fox Valley stem." Fox Valley stem is attributed to the late archaic stage, extending into the early woodland stage, about 7000 to 100 BC. The other two on this slide are Wabesa contracting stem points. In Wisconsin, these were often found in conjunction with early woodland, black sand, light pottery, and date from about 400 BC to AD 200. Okay, hm. 

I must have taken out a slide there, didn't intend to. Total of 16 small points exhibit many of the diagnostic attributes, such as blade shape, thickness, and stem treatment, of the Durst stem point type, generally attributed to the late archaic stage. Jim Stoltzman has suggested an interval of 1000 to 300 BC based upon radio-carbon dates obtained from the Preston and Lawrence 1 rock shelters. Seven small stemmed points were recovered. Similar small stemmed predictor points are typically associated with both late woodland and Oneota sites in eastern Wisconsin. Usually at sites associated with -- phases, small stemmed points occur in lower frequencies than triangular projectile points. Dave Overstreet has suggested that these un-standardized tools may have functioned in a variety of contexts within the eastern Wisconsin Oneota phases. Nine small points with distinct shoulders were recovered, and as with the small stemmed point discussed above, these small, shouldered points are typically associated with both the late-woodland and Oneota sites in eastern Wisconsin. Oh, there's the one. It got just out of order. 

Here's three expanding stem points. Our examples of Preston or Monona stem point types defined in southern Wisconsin. These points are associated with late archaic tradition and dated to about 1500 to 100 BC. A total of eight small projectile points. Small, un-notched points with a general isosceles triangle form have a wide distribution across North America. The term Madison triangular is most commonly used to describe the point east of the Mississippi River. Madison triangular points date from about AD 750 to 1700, expanding the late-woodland and Oneota traditions and continuing into the early historic period. A total of 20 points were identified which exhibit primarily uni-facial retouched to otherwise unmodified flakes. Small flake points are generally associated with the late pre-contact period including the late-woodland Mississippi, Oneota, and early historic. This point type dates from about AD 750 to 1700 again. 

If you look at the scale, you can see that's one inch. These are pretty small points, particularly this one. That's it sitting on top of a 1908 Indian head penny. This is very tiny. The flaking, you can see the flake scars on the point. It's marginally retouched. Some of these flake scars are so small I really have no idea what kind of tool they could have used to retouch the piece. It's very impressive to me. A total of 162 bi-faces or bi-faced fragments were recovered from the site. All stage of bi-facial reduction are represented. 

Initial edging stage. So this is kind of the sequence you would go through in producing one of the projectile points. You'd start out with a rough bi-face like this and that would be refined further and further and you'd end up with a pretty formal, thinly, fine-made tool. We had four drills we recovered. Drills are long, very narrow, elongated bi-faces with a thickened cross-section. 20 small scrapers were recovered. These would be used to scrape hides, preparing hides to make clothing, etc. These are at the top. This one in particular is noteworthy in that it is made from a --, which comes from North Dakota. We've got an example of a couple gravers at the bottom. 

This one likewise is an exotic raw material, Burlington chert, that comes from around the St. Louis area in Illinois and Missouri. Pottery from the site. About 14,000 sherds were recovered. The majority of them were grit-tempered sherds, but we did get some shell as well. About 5% of the pottery was shell-tempered. The difference being, shell tempering is a late Oneota type pottery and it was pretty much localized at the far western part of the site. Analysis of 208 rim sherds form the basis for identification of 59 discrete vessels. The top two are some of those shell-tempered vessels. And then the rest of these are grit-tempered examples. 

We identified 14 vessels as -- collar types. They have heavy cord impressions along this collared rim. That's not what I intended to do. The -- vessels date from about AD 900 to 1200 at the end of the late mature woodland period and into the final late woodland stage. Another 14 vessels were identified as middle woodland Kegonsa stamped or Shorewood cord roughing pottery. These are earlier, much plainer, thicker vessels. They date to a period of around AD 100 to 200. And then approximately nine vessels were identified as Madison ware, Madison cord-impressed, Madison plain vessels. Often associated with effigy mound culture in Wisconsin, they date from around 700 to 1000 AD. And there's some more of those. 

And the largest piece of pottery that we did recover from the site. About eight vessels were small, miniature vessels, pinch pots. Usually contained no temper whatsoever. Nine of the vessels exhibit very thin walls and an estimated orifice of 5 cm or less. The decoration was noted on six vessels consisting of cord impressions, fine incising, fingernail impressions and lip notching. Some of the other artifacts recovered from the site include two clay beads. No temper was in that paste. One fragment of a smoking pipe was recovered. The pipe was made of a native clay tempered with a light amount of fine dark material. It represents a plain, hand-made bowl with a rounded lip and somewhat rectangular portion of the base or stem. 

Some of the early historic materials include a brass tinkling comb, a piece of hammered, rolled lead. A gunflint. And then there were several pieces of pipe stone, which outcrops in Wisconsin in the northwest part of the state or there are the more famous pipe stone quarries in Minnesota. There's this large stone pendant, which is made of a kind of silt stone, and it's marginally retouched. Kind of looks like a side-notched point. Don't really know much else about that, what it really represents. There were three bone tools, well, two bone tools, a shell bead, and then two pieces of work bone. This was probably an awl and then this one has a hole drilled through it. Not sure. Before I get to the radio-carbon dates, we did find a fair amount of other final material. 

Most of it was pretty fragmentary. About 5000 pieces of bone were recovered, the majority were burned or -- representing food remains. Species included white tailed deer, muskrat, raccoon, black bear, domestic dog, rabbit, indeterminate rodent, bowfish, freshwater --, sunfish family, perch family, catfish, bullhead, painted turtles, softshell turtle, some mussel shell. Six samples of charred organic material were submitted for radio carbon dates. The samples were selected from feature contexts that also contained diagnostic artifacts that represented a range of cultural components. The features included three cooking or roasting pits, two rock hearths, and one processing pit. To improve the reliability of the absolute dating, samples were comprised of charred annuals such as corn, a hickory nut shell. The resulting absolute dates indicate the presence of late archaic, early, middle, late woodland, and late woodland Oneota occupations. So you can see we have this one late archaic date down here around 1000 BC. The middle woodland and the early centuries AD, and then the late woodland and Oneota dates of around 1000 to 1200. 

This is what the site looks like today. The highway is back over here. Brooks Road goes over the highway. The site that we excavated is in this area and this is what remains. When considered as a whole, the cultural deposits and artifact assemblage suggest considerable continuity of the site function during the successive occupations. Indications of seasonal occupations of this site are found in the preserved botanical remains. The presence of considerable amounts of pottery suggests that onsite activities included the storage and preparation of food. High densities of nut shell fragments recovered from feature context suggests the seasonal exploitation of these resources. The collection and onsite processing of nuts would typically have taken place in the fall, as the nuts would have ripened and been ready for harvest. The use of stored plant resources such as corn, coniponium, and wild rice also suggest a cold season occupation of this site. 

The Skeleton Bridge site likely functioned as a short-term camp associated with hunting and processing of game and the harvest and processing of local plant and nut resources, and retooling. The small site may have functioned as a satellite locus of a larger base camp or as a short-term station on a seasonal round focusing on high-yielding resources along the creek and associated wetlands. Although evidence of over 8000 years of human occupation was recovered, only 79 features were encountered. Most of the features appear to be shallow hearths or simple cooking/roasting pits, and there was an absence of deep storage pits. When these factors are considered, the transient, ephemeral nature of the site becomes apparent. Our investigation included the excavation of 27% of the total site area, leaving approximately 73% unexcavated. The portion of the site located within the agricultural field has been adversely affected by modern agricultural practices and lacks the potential to yield significant information regarding Native American life ways in the region. However, the Skeleton Bridge site still contains rich and varied cultural deposits. Approximately 620 square meters of the site occupy the woodlot situated south of the excavation block in the area that's still wooded now. This portion of the site retains the potential to yield significant information concerning the seasonal occupation during the late Paleoindian, late archaic, early woodland, middle woodland, and Oneota stages. 

And that's it, thank you. 

(applause)