Archaeologically sensitive areas contain one or more variables that make them likely locations for evidence of past human activities. Sensitive areas can include:
 

• places near known prehistoric sites that share the same valley or that occupy a similar landform (e.g., terrace above a river);
• areas where historic maps or photographs show that a building once stood but is now gone as well as the areas within the former yards around such structures;
• an environmental setting similar to settings that tend to contain cultural resources (e.g., well-drained places with highly productive soils near the confluence of two waterways); and,
• locations where Native Americans and published sources note sacred places, such as cemeteries or spots of spiritual importance.

What is a Phase IB Field Investigation?
 
 

Each project's sensitivity assessment must be field tested to verify the presence/absence of archaeological sites. Various methods are used to accomplish these investigations:
 

• Systematic Surface Survey. This method is used in previously plowed areas. Replowing and disking may be needed to improve surface visibility to about 70%. Archaeologists identify, map, and collect artifacts to identify artifact concentrations within the project limits. Archaeologists also must excavate a sample of subsurface test pits to characterize the soil and/or artifact layering present in the project area
• Subsurface Testing. This method involves manual excavation of small test pits at fixed intervals not to exceed 15 meters (50 feet). These shovel test pits can either be round or square and measure between 30-50 centimeters (12-20 inches) in diameter. The soil must be screened through ¼-inch mesh to standardize the recovery of a full range of artifacts. In some urban or floodplain situations, backhoe trenching or other machine-assisted methods may be necessary to reach deeply buried cultural resources.
• Remote Sensing. This testing method is used to identify buried features without destructive excavations. Fragile and sensitive cultural features, such as burials, are the types of cultural resources that could be severely damaged by subsurface discovery methods. The tool most commonly used in this process is ground penetrating radar. Remote sensing may not be appropriate for all field situations and experts should be consulted before these techniques are used. When remote sensing is selected, field verification through excavation of the resulting anomaly areas is necessary to verify that these patterns are cultural.
• Laboratory Processing. Archaeologists must clean, stabilize, and inventory all cultural material removed from the field. An artifact catalog notes the location of each piece (e.g. shovel test pit number or surface collection spot), the depth at which it was found, a description of the piece, as well as other pertinent information. This catalog should use terms commonly used by other archaeologists and current with the state-of-the-art. All collections, including artifacts, field records, and photography must be curated in a repository that meets the requirements of the Standards.
• Report. At the conclusion of all investigations and processing the archaeologist must produce a written report that complies with the Standards. This report will contain a summary of what (if anything) was found and recommendations about the next step in the process. This summary document is reviewed by agencies and their decision determines whether a permit is awarded or if further work is needed. Similar reports are required for all phases of archaeological investigation. Details on what should be included in these reports are discussed in the Standards (Section 6.0)

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