4 BUREAU OF AMERICAN ETHNOLOGY [Bull. 182 



The normal annual rainfall for the Eoanoke River Basin above the 

 damsite is approximately 43 inches. It ranges from 41 inches at 

 Roanoke, Va., to 60 inches at Randolph, Va., both of these extremes 

 occurring in the western portion of the basin. It averages 44 inches 

 at the damsite while the maximum annual rainfall, averaged over 

 the basin, was 54 inches in 1937, and the minimum was 27 inches in 

 1930. 



Moderate and extreme temperatures occur in the Roanoke River 

 Basin. The highest temperature recorded in the basin was 107° 

 at Weldon, N.C., and Danville, Va., and the lowest was —12° at 

 Roanoke, Va, 



GEOMORPHOLOGY 



The Roanoke River rises on the eastern slopes of the Appalachian 

 Mountains, flows in a southeasterly direction toward the Atlantic coast, 

 and empties into Albemarle Sound approximately 7 miles below 

 Plymouth, N.C. The principal tributary, the Dan, rises m Patrick 

 County, Va., flows eastward through sections of North Carolina and 

 joins the Roanoke River at Clarksville, Va., about 200 river miles 

 above the mouth. The upper Roanoke River, between Altavista and 

 Clarksville, Va., is known locally as the Staunton River and was 

 named in memory of the wife of the late Governor of Virginia. 



A small portion of the drainage basin lies in the rugged terrain of 

 the Allegheny and Blue Ridge Mountains, and the larger and longer 

 portion is confined to the Piedmont Plateau. The Plateau, a rolling 

 to hilly country with elevations ranging from 300 to 900 feet above 

 mean sea level, is traversed by highlands and cut by numerous tribu- 

 tary valleys. The flood plain along these two streams in the Piedmont 

 Plateau ranges from 1,400 to 2,000 feet in width, while the river 

 channel varies in width from 100 feet in the upper reaches to about 

 800 feet in the lower. 



PHYSIOGRAPHIC ENVIRONMENT OF THE ROANOKE RIVER VALLEY 



With Fenneman (1938, p. 9) as the authority, it has been stated 

 that physiographically the Roanoke River valley lies in the mid- 

 Athmtic part of the Atlantic Coastal Plain which "is often spoken 

 of as the newer margin of the continent, a relatively recent addition to 

 a growing mass." 



Pleistocene terraces. — Throughout tlie Coastal Plain south of the 

 glacial border, the surface is more or less terraced, and in the Southern 

 States it forms a broader, straighter, and more continuous band than 

 among the numerous estuaries around Chespeake Bay and represents 

 intermittent or oscillating witlidrawals of the sea. Underlying ma- 



