What is an STP

Shallow STP excavation at Hopewell Furnace National Historic Site

Today we want to talk a little more about one of the most tried and true survey methods ever to grace our discipline: the shovel test pit. Shovel test pits, or “STPs,” function to give us an idea of what is underground quickly, efficiently, and inexpensively. All you really need is a screen, a shovel, and a trained archeologist!

So how do these work? Essentially, an archeologist grids out an area a set number of meters apart, then excavates STPs until cultural material is found. If cultural materials are discovered, typically the next step is called digging “radials,” or STPs spaced about 2.5 and up to 5 meters in each cardinal direction away from the original STP location where artifacts were discovered. Most of the time, a tarp will set up next to the location of a STP to be dug, and the dirt excavated from the STP using a shovel will be screened through a ¼ inch shaker screen to search for artifacts. All the dirt excavated from the STP will be used to refill the hole to prevent any negative impacts to the landscape and to wildlife, even wildlife interested in starting a new career as an archeologist.

In the Northeast, STPs are typically required to be excavated by hand up to one meter deep at which point it’s too difficult for an archeologist to excavate much deeper. The STP is one survey method that is indispensable in an archeologist’s methodological toolbox, and one that has sent many an archeologist into a warm bath to cure muscle aches after a day of digging a couple dozen of them.