North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: Fort Laramie National Historic Site, WY;
Reference: Somers, L.E. (1998). Geophysical Remote Sensing Survey of the Quartermaster Depot Dump at Fort Laramie National Historic Site. In Archaeology at the Fort Laramie Quartermaster Dump Area, 1994-1996. D.N. Walker, ed. pp. 81-90. U.S. Department of the Interior, National Park Service, Rocky Mountain Region, Division of Cultural Resources, Selections Series, No. 13, Denver, Colorado.
Archeological investigations were conducted at Fort Laramie National Historic Site, Goshen County, Wyoming, in 1994 and 1996 along a portion of the north bank of the Laramie River, just below the main fort area. This portion of the riverbank has been long known, perhaps erroneously, as the "Quartermaster Depot Dump. " Investigations were initiated to mitigate the effect of stream bank erosion on archeological resources along the Laramie River in this area of the park. The 1994 investigations were the latest in a long series of Fort Laramie archeological investigations that began in 1939, shortly after the property was acquired by the National Park Service. The dump episodes along the riverbank examined during the present study came from several localities throughout the fort. There was also no known record of when these dump episodes occurred.
1994 archeological investigations began with magnetometer and soil resistivity studies. Soil resistance studies were inconclusive in locating military features in that most soil electrical resistance differences across the project area can be attributed to latest 19th and early 20th century homesteading activities. Magnetometer data proved more useful in interpreting a historic dump feature than soil resistance data. Distinct clusters of metallic objects were identified and shown to be scattered over the project area. More than twenty of these metallic clusters can be identified along and near the riverbank. Systematic eight-inch auger probes placed along the riverbank between the known metallic concentration areas showed no major significant artifacts in the areas that are devoid of metallic objects between concentrations. Augering next to known concentrations yielded relative high numbers of artifacts. Further away from these magnetometer identified concentrations, augering yielded little or no numbers of artifacts.
The application of GIS (Geographic Information Systems) to studies of archeological remains at historic sites was shown to be a valid technique to be used before archeological field investigations. By overlaying a series of historic maps, compiled and adjusted for mapping error, proper location of historic structures can be postulated. Using a single map to identify the location of a structure resulted in locational errors of several tens of meters. While it may not be exactly where that historic structure was originally located, the probability of its predicted location being more accurate than any one map is higher using GIS overlays. Use of this technique in this study was a direct benefit to determining where the Adobe Corral might be preserved.
While lithic tools and other debris that could be attributed to Native American manufacture were recovered from several of the test units, no evidence was recovered suggesting any long term Native American occupation along this portion of the Laramie River bank. Three features distinctly related to post-military occupation were recorded: an elevated irrigation ditch constructed around the turn of the century, a concrete headgate for an irrigation lateral ditch leading from this main elevated ditch, and the 1960s plow zone where attempts were made to loot historic bottles from the dump area before its transfer to federal ownership.
Military era structural features recorded are represented by a wagon yard fence/wall section and a postulated livestock stable area. Ditches of unknown origin (but Euroamerican) and use were recorded were also recorded. Three features, probably military in origin, were also recorded along Backhoe Trench Two, but not investigated.
Perhaps the most significant finding was the identification of structural remnants of the "Adobe Corral." The north wall of the Adobe Corral lies under the elevated irrigation ditch and , and most of the Adobe Corral has eroded into the Laramie River in the past 20 years, primarily during the 1984 flood.
All historic dump features located within Excavation Blocks One, Two, Three and Four along the riverbank in the project area have been adequately, or in some instances completely, tested or excavated, although some remnants still remain. Additional work on these specific features within these excavations blocks is not warranted. Highly significant to the overall purpose of this study was the finding that major portions of this terrace immediately next to the riverbank do not contain significant archeological deposits. For many years, common thought was the dump was continuous along the entire length of the riverbank in this part of the fort property. We now know the dump deposits are discontinuous, with a large part of the riverbank having no archeological deposits. This is highly important for the mitigation of the riverbank erosion problem. Twenty-seven features were recorded during the 1994 excavations at the Fort Laramie Quartermaster Dump area. Most of these (17) are individual dump episodes of trash cleanup from the main fort area, representing military (both officers' and enlisted men's) household items and civilian (post sutler's) trade items. Artifacts from these dump episodes date from the 1880s, although portions of at least one dump episode also contains 1890s era artifacts. It is possible an additional minimum of twenty dump episodes remain unexcavated within the project area examined by the remote sensing. These 20 magnetometer identified dump episodes may represent over 60 individual dumping activities.
Perhaps most significant to the overall goals of these investigations was determining that no data were present showing this portion of the Laramie River bank can actually be identified as a "Quartermaster's Dump." All dump episodes show characteristics of being from living quarters or Sutler area cleanups and not activities consistent with the reported procedures for disposal of Quartermaster goods. If there is a "Quartermaster's Dump" at Fort Laramie, it was not along this specific part of the Laramie River bank.