e. the Norfolk Peninsula--This peninsula is located between the James River and the Virginia-North Carolina boundary line. In general, the land in this region is a flat plain. The tidal rivers mentioned previously are actually estuaries of Chesapeake Bay and they flow periodically inland. Therefore, they are an unusual combination of waters from the Bay itself and from the Atlantic Ocean whose pressure pushes the tides inland. The strong influence of geography upon occupations in this region is exemplified by the importance of commercial fishing (especially oysters, scallops, clams and crabs), ocean transportation (the large area of deep water in the Chesapeake Bay encourages ocean-going commercial ships to seek inland ports in this region--especially around Hampton Roads), truck farming (the clay loam soil and the sandy loam soil here provide excellent productivity of potatoes, early vegetables, corn and hay), and the manufacturing of fertilizer (particularly from fish and fish scraps), bricks (an abundance of sand and gravel encourages the making of bricks), pulpwood, railroad ties, barrel staves and other lumber products (60% of the Tidewater area is covered with forests). (2) the Piedmont Plateau--This region extends from the Coastal Plain westward to the foot of the Blue Ridge Mountains. The word "Piedmont" literally means "at the foot of the mountain." A plateau is defined as a high lowland; therefore, this section is higher in elevation than the Coastal Plain region. This area is characterized by rolling hills and many swift streams. The width of the plateau varies from forty miles in Northern Virginia to one hundred ninety miles in the southern part, gradually broadening as one travels southward. The plateau rises gradually from an elevation of 200-700 feet at the eastern end of the plateau until, at the foot of the Blue Ridge Mountains, it reaches approximately 1500 feet near the Virginia-North Carolina border. The Piedmont area located south of the James River is known as the Southside. Agriculture is the chief occupation because, in general, this land is fertile due to the presence of limestone soils and clay deposits. Large amounts of tobacco are grown here. The Piedmont also has a great variety of rocks, including granite and soapstone which are currently commercially important.