During the summer of 1936 the Montana Archaeological Survey, then under the direction of the late H. Melville Sayre, investigated a campsite on the ranch of John Trask about nine miles above the mouth of Ash Coulee, a partly subterranean tributary which enters the Yellowstone River about three miles above Terry, Montana. The excavation was under the immediate supervision of Raymond Thompson. Due to unexplained circumstances field notes of this investigation were not preserved. Description of the manner of excavation was obtained from Thompson who excavated the site in a thoroughly scientific manner and who is not responsible for lacks in documentation. The writer was not present during the investigation and has seen only the artifacts in the Survey's collections. Though documentation is meagre, the recovered material is significant enough to the problem of westward movements of prehistoric ceramic cultures into the northwestern Plains to warrant description.