1. Sinkholes and karst-related features of the Shenandoah Valley in the Winchester 30ʹ x 60ʹ quadrangle, Virginia and West Virginia Yale Public content 1994. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Map Distribution. English. Public. Shenandoah River Valley (Va. and W. Va.).