LiDAR predictive modeling of Pacific Northwest mound sites: A study of Willamette Valley Kalapuya Mounds, Oregon (USA)

Archaeologists need new methods to survey large areas and overcome environmental and archaeological barriers to site discovery in heavily forested regions. LiDAR (light detection and ranging) technology is one possible solution to these challenges as LiDAR digitally clears away vegetation, facilitating large-scale remote sensing survey. The Calapooia Watershed, located in the southern Willamette Valley of Oregon, is an ideal area to utilize LiDAR. While valley lowlands are cleared for agriculture, riverine areas remain heavily wooded and are known to contain hundreds of low-lying earthwork features created by pre-colonial Kalapuyan people. To assess the potential application of LiDAR in this region, we developed and tested a mound detection predictive model using LiDAR and aerial imagery. Field testing of the model identified seven new Kalapuyan mounds and verified the location of several others. Our model was 44 percent successful in identifying cultural mounds and 100 percent successful in identifying extant previously identified mounds. The model is effective and can be used to identify and preserve mound features in the Pacific Northwest; the model can also be modified and used to identify earthwork features in other regions.