Archaeological Data Recovery Plan for Work Associated with Placement of New Septic Holding Tanks near the Caretaker's House and Repairs to the nearby Wellhouse Foundations at the American Fur Company Headquarters (21 DK 31) site (Sibley House)

Project Background

This project will involve 100% mitigation of planned areas of disturbance at the American Fur Company (21 DK 31)/Sibley House Caretaker's House and Well House. The caretaker's house area is on the property between the Henry Sibley House and the J.B. Faribault House in the Mendota Historic District. Work on this project will essentially involve archaeological excavation of the holes for placement of the holding tanks and the trenches around the well house prior to wall repair, processing materials recovered, and writing a report on the excavations.

The area of potential effects to be archaeologically excavated is approximately 7 meters by 3 meters (24 feet by 10 feet) in area and approximately 1.5 meters (58 inches) deep (the known depth to bedrock at this location), based on the size of the two holding tanks, necessary access space to work on the tanks, and connecting lines. Some of this area has seen prior disturbance from a now-failed septic tank that will be removed. The other area to be excavated is along the East and North walls of the wellhouse prior to wall repair. The area to be excavated is a total of approximately 5 meters in length, to be excavated approximately 1 meter wide from the walls out, to the depth of the foundation, which is unknown at this time, but expected to be no more than .5 meters.

Environmental Setting

The site is located along the Minnesota River near its confluence with the Mississippi River MnDNR, Division of Waters: 20 (Mississippi River-Metro). The environment on which the site sits is essentially riverine on a terrace and bluff-base, on Glacial River Warren. The area has been heavily disturbed by cultural activity. Rockton loam, defined for the site area in the Soil Survey of Dakota County is a gently sloping, well-drained soil on convex shoulders and backslopes of bedrock-cored terraces or uplands. This soil formed in a mantle of loamy glacial drift normally underlain by limestone bedrock.. Individual areas of this soil are irregular in shape and range from about 1.25 to 20 hectares. However at the Sibley-Faribault complex, the soils are underlain by a lag deposit of limestone that once formed in a fall pool below the rapidly upstream-moving waterfall that downcut through the Platteville and St. Peters bedrock formations. Typically, the surface layer is black and very dark grayish brown loam about 30 - 35 centimeters thick. The subsoil is dark brown clay loam about 48 centimeters thick which is usually underlain by limestone bedrock. In some areas limestone bedrock is less than 50 centimeters deep while in other areas is more than 100 centimeters deep. In the immediate are of the holding tank project, the bedrock is known to be at 143 centimeters from a soil core taken by contractors. Near the wellhouse, bedrock depth is unknown.

Prior Explorations of the site

Within the last decade, the Sibley House properties have seen several excavations associated with preservation and restoration projects and field training classes for students. Under the direction of Robert A. Clouse, Minnesota Historical Society Archaeology Department staff undertook archaeological excavations that documented a multi-component site containing occupations associated with the 19th century American fur trade, later historic period occupations, and at least 4 different occupations related to the heritage of pre-contact Native Americans. This report covers projects that began with initial testing in April--May 1995. A second testing phase was conducted during Spring 1996. Major excavations to document the material culture from stratified layers of this multi-component site began in June and continued through September 1996. A third season began in the spring of 1997 and continued through October of that year. Excavations near the DePuis house on the upland portion of the sites were done in 1999 and 2000. The segment of the site on the terrace where this project will be done is known to be deep, with cultural materials spanning from the region’s first human habitation through the time of the fur trade. Unfortunately, collections from these projects have been minimally processed and no reports have been completed. As described by the excavator, Robert Clouse, the site consists of a thin layer of recent cultural material near the surface, about 50 cm of sterile material, and then about a meter of Precontact materials.

Prehistory/History of the Site

The site (21 DK 31) is well-stratified and contains identifiable horizons associated with multiple 19th century occupations. The 1997 excavations further defined the extent of those deposits and located the remains of three heretofore unknown structures. Below these levels is more than 1 meter of natural soil with a least 4 pre-European contact Native American habitations. These occupations have been identified as belonging to the Late Paleo-Indian, Archaic and Woodland Periods. Excavations have utilized stratigraphic methods and documented cultural strata relationships with the Harris Matrix recording system. Materials excavated earlier are accessible in Museum Collections at the Minnesota History Center and at the Archaeology Department, Historic Fort Snelling. Associated documents, maps, photographs, and field notes are also available. Dr. Clouse has said that he will be available for questions or other consultations.

Research Questions

The research questions to be addressed are essentially a continuation of those asked by Clouse's excavations. Because of the discrete nature of deposits existing at the site, it is possible to address a broad range of issues relevant to the application of archaeological methods, the reflection in archaeological data of historically documented activities, and anthropological questions related to concepts of culture change. Some of the major research areas to be addressed are 1) changing subsistence practices, 2) changing material culture resulting from variable access to and differential sources of supply, 3) changes reflected in the site from its frontier setting to one that becomes a part of an urban setting, and 4) changes from a commercial to a residential function. Examples of specific questions to be addressed are: How does the artifact assemblage reflect the change from a commercial to a residential site function? What is the relationship of the Sibley/Faribault development to the earlier fur trade operations and development of Alexis Bailly? What are the nature, extent, and condition of the different components of the site?

Data Recovery Methods

Standard data recovery methods will be used, but at the discretion of the Principle Investigator. At minimum this means:

· Units should be excavated in 10 cm levels unless natural or cultural stratigraphy indicate that another approach would be more useful.

· Piece plotting of all artifacts and mapping of all features.

· Photographs of each level (digital preferred) and feature.

· All excavated soil should be run a sifter screen.

· Collect soil and process soil samples as warranted by soils and features.

· Radiocarbon dating should be used where samples warrant (a minimum of three samples from holding tank areas if possible).

· The use of the Harris Matrix recording system is left to the discretion of the principal investigator due to the controversial nature of the approach.

· Once the sterile stratum(a) are confirmed, the excavator may employ mechanical methods (e.g., backhoe) for removing the level; a preferred alternative would be to hand excavate the material rapidly by shovel.

All artifacts will be processed according to MHS Museum Collections Department standards and will be curated at MHS. We intend that this work be completed as early as possible in the spring of 2004, with May 15 as a target date for completion of all field work. The report is due by September 1, 2004.

Related Considerations

Because of the malfunction of the septic system at the site, sewage may have contaminated soils around the old septic tank. Excavators have been warned to take necessary precautions to protect the safety of workers in that area.

Larry J. Zimmerman, Ph.D., RPA

Head, Archaeology Department

Minnesota Historical Society

Ft. Snelling History Center

St. Paul, MN 55111

Phone: 612-970-2843 or 651-297-7451