Continuous prehistoric occupation of northern Ohio from 9000 B.P. to 5000 B.P. has often been quesitoned. Its demonstration is difficult to support. Stratigraphically intact archaeological evidence for this Late PaleoIndian-Early Archaic period is not common in the eastern United States and is generally found in dry rockshelters or in alluvial bottomlands. In northern Ohio, rockshelters are rare and bottomlands have recently been subjected to deep-plowing. The controlled comparative germination of viable seeds in such recently disturbed strata yields an Index of Plowing which can determine the lower limits of such disturbance in the absence of other pedological or archaeological indications. The application of this Index to the Norman P site in Summit County, Ohio, reveals an intact PaleoIndian-Archaic Transitional occupation.