The rusted lid of a container of baking powder is shown Oct. 27, 2015. The artifact was discovered at a Fort McCoy, Wis., archaeological site in 2014. The lid dates from the 1930s-1950s. (Contributed photo)

In 2014, archaeological researchers with Colorado State University’s Center for the Environmental Management of Military were investigating an archaeological site near the Sparta-Fort McCoy Airport to determine if it was eligible to be listed in the National Register of Historic Places.

The site had been identified a year earlier and produced a small number of artifacts commonly recovered from historic sites elsewhere throughout the installation, such as homesteads and farmsteads that belonged to some of the early European-American settlers in the region.

One notable feature of the site was a depression, or dip, in the ground surface that was roughly square in outline. Depressions can indicate a variety of things, such as the dug-out floor of a structure or a dump area families in the area disposed of their waste. In this instance, the depression was a dump area and was full of a wide variety of historical materials.

One of the items of particular interest to archaeologists was the metal lid of a baking powder container. This container lid has raised lettering that was still legible, despite significant oxidization or rusting. The brand name “KC BAKING POWDER” and the words “TRUE HEIGHT CAN GUARAN-TEED” can be read. What is significant about this is that the KC Baking Powder cans had regular alterations to the design of the lid, which serve as temporal markers, a sort of boundary for the time period the lid was produced and sold. This particular lid style was in use from approximately 1930-1950.

KC Baking Powder was initially manufactured by the Jacque Manufacturing Co. in Chicago beginning in 1890. There are several examples of lids from the manufacturer, which detail how long the product was sold. This helps researchers determine almost exactly when people were living at or using a specific location. Archaeologists refer to these temporal markers as diagnostic attributes, in that they can diagnose something with great accuracy.

Another company that made or used products or packaging that serve as strong temporal markers was the Coca-Cola Bottling Co. The form of their bottles changed regularly, and the history is clearly recorded in patent records. A Coca-Cola bottle was also recovered from the depression, and the particular bottle style was in use only from 1915-1917. This means that the depression was used by one or more families from the area for at least 13 years. A number of artifacts with other diagnostic attributes, such as maker’s marks on the bases of glass bottles, a patent number on a pocket watch, and a trademark on a polishing wax tin, all supported the theory that the dump area was in use for at least 13 years and perhaps as long as 49 years.

All archaeological work conducted at Fort McCoy is coordinated by the Di-rectorate of Public Works Environmental Division Natural Resources Branch (NRB).

Visitors and employees are reminded they should not collect artifacts on Fort McCoy or other government lands and leave the digging to the professionals. Any person who excavates, removes, damages, or otherwise alters or defaces any historic or prehistoric site, artifact, or object of antiquity on Fort McCoy is in violation of federal law.