Integrating Results
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The combined maps of surface artifacts and subsurface geophysical anomalies creates a good opportunity for interpreting the Garden Coulee Site within Fort Union Trading Post National Historic Site. As mentioned in the History section of this page, archeologists have documented several archeological features representing bell-shaped storage and refuse pits as well as other archeological signatures associated with the historic Crow-Flies-High band occupation. Previous investigations provided significant information about parts of this site but did not determine its total size. The 2002 project covered a very broad area, and successfully delineated the spatial extent of artifacts and features associated with the Garden Coulee Site. Data gathered during this project integrate previous knowledge into information available for the rest of the site to create a very useful planning tool for park management.

Surface artifact mapping demonstrated a dense scattering of artifacts across much of the area, especially the southern and western portions. Although no mapping was conducted within the active roadway, many artifacts were noted on the road surface as well. Overall, the mapped surface contained 648 artifacts, some of which clustered into two concentrations. The largest cluster is near the western boundary of the investigated area, measuring over 7000 square meters. The second cluster, near the terrace edge to the east, is smaller, at approximately 240 square meters.

These clusters are not necessarily isolated however. It is hypothesized that dense vegetation obscured the ground surface over much of the space dividing the two concentrations, limiting the documentation of artifacts through this area. This hypothesis is supported by a metal detector survey (figure), covering a portion of this space just north of the existing road. This 160 square meter test plot recorded 310 "hits," indicating that dense artifact

Metal detector survey block N1000 E1120 showing metal detector points.

Combining geophysical information with the surface artifact data refines our knowledge of the archeology of the Garden Coulee Site. The figure to the right shows three Magnetic Anomaly Concentrations (MAC), two of which (A and C) overlap with the surface artifact concentrations. The third MAC, labeled "B," overlaps with the area investigated by metal detector, and also likely contains a concentration of artifacts. MAC A and Surface artifact concentration (SAC) #2 may correspond to the Garden Coulee Site, as it is located near the features identified in earlier studies, although further testing is required to confirm this. MAC B as well as the surface and near-surface artifacts implied by metal detector survey also corresponds with the same site, as it contains all of the features previously identified.

Distribution of magnetic anomalies in the Garden Coulee site area showing surface artifact concentrations (green), concentrations of magnetic anomalies (blue), and modern road and waterline routes (black).

While the multiple data sets overlap, they also diverge. Studying their interaction provides insight into the subsurface archeology. Surface artifact concentrations in the absence of geophysical anomalies may indicate the presence of shallow cultural features, such as middens (discard areas) or places where certain activities were performed. Alternately, they may be the result of more recent agricultural activity such as terracing, which would have transported and concentrated surface materials during the course of shallow earth moving. On the other hand, magnetic concentrations in the absence of surface artifact concentrations might indicate the presence of deeper features such as storage or refuse pits. Ground-truthing (excavating test units) in key areas would be the next step toward answering questions concerning the relationship between artifact distributions and geophysical anomalies..

The data presented here go a long way toward improving our understanding of the historic resources related to the Crow-Flies-High band occupation and provide key knowledge necessary for effective management and planning. The park now has critical information regarding the ongoing impact of the active roadway, and probable impacts of any new trails traversing this area. As this site comprises the only existing archeological evidence of occupation for the Crow-Flies-High band, and it represents such a pivotal time in United States and Native American history, it is a significant and valuable resource. NEXT >>