The unique identifier for the given observation point. Consists of the survey unit designation ("S"NNNN) pluse observation point (<transect>NN). Thus, S0001-A2 is the second observation point in the A transect in survey unit S0001.

'Observation points' summarize artifact field counts made by the fieldwalking team during the course of investigating a given survey unit. Every 15 meters (measured by pacing), fieldwalkers summarize the numbers of artifacts observed in the previous 15 meters, thus creating a rough grid over the survey unit. Lines walked by the fieldwalkers (transects) are labled with letters, and begin at the lower right corner of the survey unit. Thus, S0201-A04 is a point found in survey unit S0201, first transect (A), fourth observation along that transect. This information was then recorded into the GIS.