Dr.Kenneth M. Ames, Portland State University, and crew
Dr. Doug Wilson at the Middle Village/Station Camp archaeological site. Courtesy of Dr. Douglas Wilson

Archaeology is the scientific study of human history through site excavation, identification and analysis of artifacts, tools, plants, animals, and other physical traces of human presence.

Archaeology reveals much about Chinookan history and culture but how do archaeologists decode the past?

Archaeologists use scientific methods to examine the remnants of human communities and interpret their findings in relation to other historical methods, like examining written documents and consulting community members.
Archaeologists first locate a site and then systematically excavate test units for comparison of objects (artifacts) left behind. Site location begins with a visual survey. Archaeologists look for earthen mounds, depressions in the ground, and evidence of human occupation like discarded shards from tool making to determine where to dig. Technological advancements, like Ground Penetrating Radar (GPR) allow archaeologists to look beneath the earth’s surface. Oral history can also prove critical to finding important sites. Because many tribal members hail from places Chinook people have lived continuously for centuries, they may know of historically significant sites that are not public knowledge amidst the towns and suburbs of the twenty-first century Lower Columbia River region.

Video: Watch Dr. Kenneth M. Ames explain how archaeologists identified the location of the Cathlapotle Village in Ridgefield, Washington through oral and written sources.

Layers of Time

Layers of soil reveal patterns of daily life for hundreds of years at Cathlapotle. Courtesy of Dr. Kenneth M. Ames

The photo of the Cathlapotle dig site above shows how layers of dirt (stratigraphy) reveal landscape age. Bands of differently colored soil from bottom to top indicate the earliest to most recent eras. The levels allow for relative dating of a site that reveal cultural evidence at different points in time. Objects like beads, elk bones, and house post holes can indicate stages of occupation and interactions with distant peoples. Stratigraphy also reveals environmental changes, such as water levels, volcanic eruptions, and earthquakes like the one that took place on the Lower Columbia on January 26, 1700.

Once an item is found it must be labeled, packaged, and readied for lab analysis. Carbon dating and forensic geology are important methods for determining the age of organic materials. Because C-14 (carbon) isotopes are in every living thing, scientists can compare how much C-14 exists in organic remnants compared to living organisms. They use the “half-life”– how long it takes for half the carbon to disappear (5,730 years) – to determine age. Unlike other dating techniques, carbon dating gives an absolute (or numerical chronological, rather than relative) date of an artifact. Forensic Geology, the study of evidence relating to minerals, oil, petroleum, and other materials found in the Earth, also reveals the passage of time. Analyzing elements in the soil may provide clues about where an artifact came from and suggest rough periods of contact and trade.

Understanding the Results of Digging In

Archaeologists recovered this ferrous metal sword, or knife, and six metal knife fragments from a single area of the Middle Village excavation. Courtesy of Dr. Douglas Wilson

Archaeologists have discovered thousands of artifacts that reveal what people ate, how they cared for their homes, who they interacted with, and how long they lived at Cathlapotle, Middle Village, and other sites on the Lower Columbia River. This archaeological evidence is an essential and primary resource. Objects like the metal sword in the picture above give us clues about the past. The artifact is approximately 14 inches long and appears to have been plunged deliberately into the ground in one of the plankhouses at Middle Village. While things like copper bracelets and beads appear to have been lost during use, this sword seems intentionally placed, and although no one knows why, other artifact placement in the floor or in plankhouse wall trenches also appears purposeful.

As with all efforts to understand the past, archaeology has advantages and disadvantages. Archaeology can reveal much about group behavior over a long period of time, but tells us little about specific individuals at a single historical moment. For example, archaeologists found an abundance of ornamental jewelry, metal tools like the sword mentioned above and other knives, trade beads, ceramics, and ceremonial objects that indicate great material wealth at Middle Village. The significant concentrations of wealth indicates the affluence and high status of its occupants during the fur trade era (1790s-1840s). Yet we don’t know for sure if a headman like Comcomly lived in the house where the sword originated.

Archaeological evidence is limited in other important ways; it reflects the material world, but only through the questions raised by individual scholars and the answers they provide. While the deliberate placement of objects might raise questions about status and belief systems, the remnants of material culture often reveal little about how people felt regarding items left behind. Moreover archaeologists who explain patterns in the soil, the meaning of objects, and the human behaviors
they reflect also interpret the past through their own filters of time, place, training, and available technologies. Like all means of understanding the past, archaeological evidence is strongest when corroborated with other ways of knowing.