The five basic steps in any excavation are: establish a grid of squares over the entire site; remove and screen the plowed soil from the top of each square; photograph and map the soil stains (called features), which are visible beneath the plowed soil; excavate the features to recover their contents; and when everything else is finished, refill (or backfill) the excavated areas with soil. In the rest of this section, we will describe all these steps in more detail.