Land use: Most of this area is in farms. About 12 percent is used for urban development or consists of land altered by urbanization or other activities. Approximately 30 percent is cropland. A wide variety of crops are grown, mainly corn, small grains, and forage for dairy and beef cattle. Other important crops include potatoes, soybeans, apples, peaches, and some tobacco and vegetables. Dairy, beef and poultry farms are major enterprises. About 5 percent of the area is permanent pasture. Less than 60 percent is in hardwood forests that are mainly in small to medium-size holdings and some larger tracts of state forests, game lands, and parks. Much of the prime farmland in the valleys is urbanized.
Elevation and topography: Elevation ranges from 100 to 300 m in the valleys and from 400 to 800 m on ridges and mountains, but on some mountain crests it is 900 m. Parallel sandstone and shale ridges are separated by narrow to moderately broad limestone and shale valleys. Ridges have hilly to steep slopes and narrow rolling crests; valleys are mainly undulating to rolling but are hilly locally. Local relief in the valleys is about 5 to 50 m; ridges rise about 100 m above adjoining valleys.
Climate: Average annual precipitation-900 to 1,275 mm. Maximum precipitation is in spring and in summer, and the minimum is in fall. About 525 to 650 mm falls during the growing season. The average annual snowfall is 60 to more than 130 cm. Average annual temperatures-8 to 13 C. Average freeze-free period-120 to 170 days; the shorter growing seasons are at the higher elevations and in the north.
Water: Water is plentiful in this area. Springs, wells, farm ponds, reservoirs, and streams are the principal sources of water. The major streams are the Susquehanna and Potomac Rivers. Raystown Lake on the Raystown Branch of the Juniata River is one of the largest reservoirs in the area. Ground water is plentiful; the better producing wells are in the limestone valleys. Mineralized water and pollution of ground water are common land use problems.
Soils: Most of the soils are Udalfs, Udults, and Ochrepts. They have a mesic temperature regime, udic and aquic moisture regimes, and mixed mineralogy. Nearly level to sloping, deep, well drained, medium textured to fine textured Hapludalfs (Hagerstown, Duffield, Edom, and Washington series) are in the limestone valleys. Gently sloping to sloping, deep, well drained or moderately well drained, medium textured to fine textured Hapludults (Allenwood, Bedington, Frankstown, Mertz, and Murrill series), Fragiudults (Buchanan and Laidig series), and Paleudults (Frederick series) are on the lower foot slopes of the ridges and in the valleys. Most of these soils formed in residuum, colluvium, or glacial till derived from limestone, cherty limestone, sandstone, and shale. Sloping to steep, well drained, shallow to deep, medium textured Dystrochrepts (Berks, Calvin, Dekalb, Hazleton, and Weikert series) are on ridges and on the more sloping sites in the valleys.
Potential natural vegetation: This area supports hardwood forest vegetation. White oak, red oak, black oak, hickories, and associated upland hardwoods are the major species. Scarlet oak, chestnut oak, hickories, and scattered Virginia pine, shortleaf pine, and white pine are common on dry ridges and shallower soils. Yellow-poplar, red oak, red maple, and other species that require more moisture grow in sheltered coves, on foot slopes, and on north-facing sites.
(From "Land Resource Regions and Major Land Resource Areas of the United
States". United States Department of Agriculture Soil Conservation Service
Handbook 296. Dec. 1981. page 106 - 107.)