HRA conducted cultural resources investigations for the Willow Creek Dredging project in Gilliam County, Oregon. The project proponent proposed to dredge the mouth of Willow Creek to eliminate flood-borne soils, but the area was known to have been utilized by Native Americans prior to damming of the Columbia River. HRA worked with the Confederated Tribes of the Umatilla Indian Reservation to draft a detailed ethnographic history of the project area and undertake underwater archaeological investigations to explore the archaeological potential of the dredge area. The results of our work were used to ensure avoidance of archaeological resources during the dredging operation.