Phase I Archaeological Survey is the first step in the cultural resource compliance process. This level of investigation includes background research on known and potential sites and the systematic evaluation of a property to identify any cultural properties that may be located within a tract. In the eastern United States and Caribbean, the majority of archaeological sites are buried, and a survey is most frequently accomplished by excavating shovel test pits at a specified interval, which varies between 10 and 30 meters of spacing, as determined by each state. In urban locations, or where there is the potential for deeply buried sites, backhoe test trenching may also be used at the survey phase. Shovel test pits are dug using round-nosed shovels, with fill screened through 0.25-inch mesh hardware cloth for the recovery of artifacts. Tests are dug to culturally sterile soils, and, hence, survey tests in coastal regions, as well as river floodplains, will be much deeper (often to a meter plus) than tests dug in eroded upland regions (where tests will generally not exceed 30 centimeters in depth).
The methods used for an archaeological survey are adapted to the expected resource types. For example, if a tract has a high potential to contain battlefield resources, the methods will include interviews with local collectors and an intensive metal detector survey. In urban settings, Sanborn Fire Insurance Maps and other cartographic sources will be used to target backhoe trenches through modern fill.
When sites are found, additional shovel tests are dug at a tighter interval to determine site boundaries, GPS readings are taken of the site’s perimeters, photographs are taken, and a sketch plan is prepared. All sites are recorded on the appropriate state site form. A survey report is then prepared that describes the survey area, its environment and cultural history, and the resources identified. At the survey level, each site is recommended as either eligible for nomination to the National Register of Historic Places, not eligible for nomination, or eligibility unknown (“potentially eligible”). The final evaluations of site eligibility are made by the lead federal and state agencies and State Historic Preservation Office following their review of the survey report. Under Section 106 of the National Historic Preservation Act, only sites that are eligible for the National Register need to be taken into consideration in project planning.