A BRIEF GEOLOGIC HISTORY OF ROCKINGHAM COUNTY
By W. Cullen Sherwood
Dept. of Geology and Environmental Studies
James Madison University
GEOLOGY AND HUMAN HISTORY IN ROCKINGHAM
There is little question that geology has had a profound effect on human history in Rockingham County. The land use plan for Rockingham County (1975) shows a strong relationship between geology and existing land use. Most fundamental is the concentration of the population on the valley floor with comparatively low population density in the mountainous areas. Two factors are probably of most importance-first, the rich limestone soils and associated flood plain soils drew the early settlers to the Valley because of their agricultural productivity, secondly, the relatively flat valley floor made development of homes, town, and roads relatively easy.
Throughout the history of the Valley, geology has controlled the major travel routes. Indian trails and later roads and railroads have run up and down the Valley since man first moved into and through western Virginia. The route of the early German and Scotch-Irish settlers following the limestones southward from eastern Pennsylvania to the Shenandoah Valley is well documented. The east-west routes across western Virginia have equally important geologic controls. These routes traverse the mountains through the gaps cut by active or formerly active streams. In Rockingham the major east-west highway, Route 33, traverses Swift Run Gap in the Blue Ridge and the Dry River Gap through the ridges in the western portion of the county. Other gaps which have been used for east-west routes in Rockingham are Browns Gap and Simmons Gap in the Blue Ridge and Brocks Gap and Briery Branch Gap to the west. Browns gap in particular was a major route across the Blue Ridge for many years until it was closed to traffic by the formation of the Shenandoah National Park. Many secondary transportation routes show local control by ridges, hills and stream valleys. Finally, the major streams and rivers of the county served as important water transportation routes during the early years of human settlement in the Valley. Much of the early commerce such as lumber, grain, tanning bark, and wool moved down the forks of the Shenandoah river to market and to ports further north and east.
Much of the mountainous area of Rockingham is today in the hands of the federal government. Most of the Blue Ridge lies within the Shenandoah National Park and much of the Massanutten and Allegheny Mountains are in George Washington National Forest. Federal control further restricts population growth in these areas where low population density has always been the rule. That recreation, timber production, and wildlife management comprise the principal land uses at present is due primarily to geologic and topographic limitations of the mountainous areas.
Another human activity in Rockingham which has been significantly affected by geology is the production of useful minerals. This includes present quarrying and mining for sand and gravel, crushed stone, and agricultural lime in several localities. Iron was formerly mined at a number of sites around the county and zinc at two localities near Timberville. Active drilling for natural gas in now underway based on new geologic evidence and some past production near Bergton. Ocre, an iron oxide pigment, occurs at several points within the county and has been mined near Keezletown. According to Brent (1960), coal was briefly mined at Wolf Creek near the Augusta County line and has been found near Rawley Springs and Briery Branch Gap.
Geological features have played a major role in the development of tourism and recreational areas in Rockingham. First and foremost is the generally acknowledged beauty of the mountain and valley scenery of the area. The construction of the Skyline Drive by the federal government attests to this point. Caves developed in the valley limestones have also fascinated Valley visitors for years. Massanutten, Endless, and Melrose Caverns have all been or are now operating as commercial caverns. The large number of non-commercial caves have also brought visitors interested in exploring the underground environment. Skiing, backpacking, hunting, boating and a number of other outdoor activities take advantage of the appropriate geologic features of the county.
In short, many of the diverse activities in which the citizens of Harrisonburg and Rockingham are now involved, in making a living, in providing shelter, in raising food, or in providing recreation are intimately related with the geologic environment. A strong case can usually be made for a relationship between the geologic history of any area and the human history superimposed upon it. The relationship appears to be particularly striking in the case of Rockingham County where both the human history, recorded by man's hand, and geologic history, recorded in the rocks, are long and richly varied.