Excavations made in 1928 at the north wall of the large pueblo of Chetro Ketl in Chaco Canyon, New Mexico, indicated that there had been fourteen feet of sandy fill in the canyon at that point since the foundations of the pueblo were laid. Sherds in the walls of the Chaco arroyo likewise pointed to considerable fill since the occupation of the large Chaco pueblos in the late 9th to early 12th centuries. This has raised the question of rate of deposition on the valley floor and of land surface levels during and since the time of prehistoric occupation. Linked with the problem of old land surfaces was that of burials, which have been notable for their scarcity in this canyon, and it seemed that an investigation of these old surfaces might yield some information on the possibility of burial grounds deep below the present surface.