In the spring of 1926 the writer began a geological reconnaissance of that part of Virginia2 which lies between the Coastal Plain region on the east and the Great Valley on the west, and had by December, 1926, carried the work in part of the area to James River. The region comprises the Piedmont and Blue Ridge provinces. At Potomac River the Blue Ridge Province extends from Catoctin Mountain west to Harpers Ferry and is coextensive with the Catoctin-Blue Ridge anticlinorium, which is continuous from near Dillsburg, Pennsylvania, across Maryland, Virginia, the Carolinas, and Georgia. The eastern boundary is the east front of Catoctin and Bull Run Mountains and a more or less continuous series of mountains which extend from Bull Run and Clark Mountains southward to the James River near Lynchburg.
South of Bull Run Mountain local custom and certain physiographers have included in the Blue Ridge Province . . .