Archaeology at Cathlapotle

Archaeologists uncover a trench that shows the outline of one of the Cathlapotle houses | courtesy of Dr. Kenneth Ames

Within a generation of Broughton’s visit, disease decimated the Cathlapotle community. In 1851 the Carty family obtained the site as part of a Donation Land Claim, grazing cattle in meadows where plankhouses once stood. Eventually, the physical evidence of the ancient village almost entirely disappeared. Farmers repurposed plankhouse timbers or they disintegrated beneath invasive Himalayan blackberry, stinging nettles, and cottonwood trees. Members of the Carty family exposed artifacts as they plowed the land and guessed it was once home to an important Native village site. Archaeologists eventually determined the exact location, size, and the scope of the village.

Archaeologists excavated Cathlapotle in the 1990s, after using historical records, information from the Carty family, surveys, and ground tests such as auguring to determine the village site. Radiocarbon dating indicates that while there had been activity in the area for several hundred years, Cathlapotle was moved to its present location around AD 1450. Starting in 1991, Dr. Kenneth Ames and his students excavated two of the six large depressions that had contained between 14 and 16 plankhouses. The excavations reveal the village’s organization, technology, resources, and global trade connections.

Archaeological Excavations at the Cathlapotle Site, 1995. Image courtesy of Dr. Kenneth Ames

Read a description of the Cathlapotle archaeological site below:
+ Download a pdf of this excerpt: Archaeological Site Description of Cathlapotle 

From Archaeological Investigations at 45CL1 Cathlapotle (1991-1996), excerpted and modified.

Cathlapotle is located on the Carty Unit of Ridgefield National Wildlife Refuge, in Clark County, Washington. . . It sits on an abandoned levee [near the confluence of the Lake, Lewis, and Columbia rivers. . . .]

Situated on the Columbia River floodplain in the Wapato Valley bottomlands, the site surface ranges from as low as 4.4 meters ASL to upwards of 7.4 meters ASL. The U.S. Army Corps of Engineers estimates that prior to modern dam construction, the average annual flood crest would have been 16 feet (4.9meters) ASL. If this estimate is accurate, then much of the Wapato Valley, but not Cathlapotle, would have been subject to annual flooding (Hamilton 1993). The Wapato Valley floodplain averages 3.3 meters ASL. Consequently, the surrounding area of the site was and is frequently flooded (Abramowitz 1980). The flooding of February 1996 provided us with a “living geology” experiment in flooding at Cathlapotle. This “100-year flood” covered the site with seven to nine feet of water. The surface of the site was little affected beyond the deposition of less then 2-3 centimeters of alluvium, and some minor erosion. The flood caused a large number of trees to fall however. Whether this flood is at all analogous to pre-dam floods is an open question.

The Lewis River, Gee Creek, and Lake River enter the Columbia River in approximately the same place. The confluence of the four waterways creates a dynamic fluvial context in the site vicinity. For example, based on their comparison of maps from the 1853 survey to current USGS maps, Parchman and Hickey have determined that Fowler Point, downstream from the site, has been eroding. They also note that the Lewis River channel appears to be moving north relative to the Cathlapotle Site (Parchman and Hickey 1993). Additionally, Lake River appears to be migrating westward, away from the site.

The Columbia River floodplain is characterized by a mosaic of microenvironments created by a variety of alluvial topographic features. The upland zone, as defined here, is the Wapato Valley slope, which intersects the floodplain 1.8 km to the east. The gentle valley slope has a westward exposure. It is characterized by gently rolling hiss and plains that are covered with open farmland and intermixed with stands of conifers and deciduous trees.

On the Columbia River floodplain, between the valley slope and Site Ridge, lies a series of elevated landforms consisting of generally north-south levees, and an area of relatively high basalt outcrops. The elevated landforms are dense with oak and brush and are well drained. The basalt outcrops are concentrated in an area to the east and northeast of the site some as near as 100 meters. These basalt outcrops are the highest landforms in the area. The highest of these is 27 m ASL in what is called the Middle Lands just north of Gee Creek. Most of the outcrops near the site and south of Gee Creek are no higher than 9 m ASL.

Interspersed between the elevated landforms (levees and outcrops) are low lying meadows, wetlands and lakes. One large set of major wetlands are located between the basalt outcrops. Other wetlands are found to the south and southeast in broader, grassy lowlands between floodplain levees. Carty Lake is one of the largest, located 2.3 km south of the site. Farther south are Campbell Lake and Vancouver Lake.

Bachelor Island, just across Lake River, is also comprised of alluvial features but has no basalt outcrops. The island is characterized by a series of levees interspersed with long lakes, wetlands, and low meadows.

The Brush Ridge landform has been disturbed by Euro-American homesteading, logging, and the quarrying of basalt from a nearby deposit (Hamilton 1993). We would not be surprised to find the logging of the Brush Ridge landform represented in the archaeological record. The site has also been subject to artifact collection by James Carty and possible others. The 1993 excavation crew found a 1/4” mesh screen near Auger 93-16.

Given the limited nature of development on the Carty unit, it may be that the immediate vicinity of the site has much the same appearance today as it did in 1806. Currently, the Brush Ridge landform is covered by a mature stand of black cottonwood (Populus trichocarpa), and a dense understory of willow (Salix spp.), bracken fern (Pteridium aquilinum), blackberry (Rubus spp.), elderberry (Sambucus sp.), and stinging nettle (Urtica dioica). Rodents are present and disrupt the archaeological context, and mosquitos are regarded as disruptive by field workers. Given that most travelers could see Cathlapotle as they passed by on the Columbia, it is unlikely that the site itself was heavily forested at the time of occupation.

The valley and the surrounding foothills possessed high habitat diversity at the time of contact. The riparian forest which was noted in the vicinity of the village by Clark (Moulton, 1990) would probably have consisted of black cottonwood (Populus trichocarpa), willow (Salix sp.), Oregon ash (Fraxinus latifulia), and a tangled understory (Hamilton 1990). In addition, Long Meadow, adjacent to the site, is thought to be a naturally occurring clearing and was probably low grass-land habitat. However, as Hamilton (1990) notes, Euro-American alteration of such areas throughout the Wapato valley makes their precontact composition conjectural.

The reported campsite of the Lewis and Clark expedition (probably around 45CL4), upstream from the village site in a grassy low-lying area, was located near a pond (probably Carty Lake) form which the natives harvested wapato (Moulton 1990). In addition to these areas, the occupants of the village would have had access to nearby prairies, oak arbors, coniferous forests, and the resources of streams such as Gee Creek, and the Lewis, Lake, and Columbia Rivers (Abramowitz 1980).

Native inhabitants of the village utilized a variety of land, water, and airborne fauna. Abramowitz identified mammals including Rodentia and Lagomorphia, as well as blacktail deer (Odocoileus hemionus columbianus), white tail deer (Odocoileus virginianus leucurus), and elk (Cervus canadensis). Predators and scavengers included black bear (Euarctos americanus), red fox (Vulpus fulva), gray fox (Urocyon cinereoargentus), coyote (Canis latrans), wolf (Canis lupus), and mountain lion (Felis concolor). Anadromous fish were plentiful in the region, particularly chinook salmon (Oncorhynchus tshawytscha). White sturgeon (Acipenser transmotanus), longfin smelt (Spirinchus thaleichthys), and eulachon (Thaleichthys pacificus) were also locally available (Abramowitz 1980). Both Lewis and Clark mention the presence of sea otter (Enhydra lutris) pelts at the village (Moulton, 1990).

Excerpt of the Cathlapotle Site Description taken from:

Archaeological Investigations at 45CL1 Cathlapotle (1991-1996), Ridgefield National Wildlife Refuge, Clark County, Washington: A Preliminary Report. By Kenneth Ames, Cameron Smith, William Cornett, Elizabeth Sobel, Stephen Hamilton, John Wolf and Doria Raetz. Cultural Resources Series, Number 13, 1999, pages 35-36.

Works Cited:

Abramowitz, A.W. 1980. Cultural Resource Assessment of the Carty Unit Ridgefield National Wildlife Refuge, Clark County, Washington. Office of Public Archaeology Institute for Environmental Studies. University of Washington, Seattle.

Hamilton, S.C. 1990. A Meier Site Catchment Analysis. Paper presented at the 38th Annual Northwest Anthropological Conference, Eugene, Oregon.

Hamilton, S.C. 1993. Preliminary Testing of Cathlapotle, draft copy. On file at Department of Anthropology, Portland State University, Portland.

Moulton, G.E. 1990. The Journals of the Lewis and Clark Expedition, Vol. 6 and 7. University of Nebraska Press, Lincoln.

Parchman, M.C. and Hickey, T. 1993. Cathlapotle Revisited; Wapato Valley Archaeology Report No. 3. Department of Anthropology, Portland State University, Portland.