Sheet I. Geological index map to the topographical map of the Durham and Reading Hills, or South Mountains, with the bordering valleys of Northampton, Lehigh, Bucks and Berks counties, 1883 (also issued as Atlas DDD Durham Index Map in the Pennsylvania Second Geological Survey's "Report of Progress")
Sheets II
XIX. A topographical map of the Durham and Reading Hills, known also as the South Mountains of Northampton, Lehigh, Berks and Bucks counties between the Delaware and Schuylkill rivers, executed in 20-foot contours (1 map on 18 sheets; also issued as Atlas DDD, sheets II
XIX of the Pennsylvania Second Geological Survey's "Report of Progress")
Sheets XX
XXV. Geological and topographical map of a part of Northampton County with contour-line elevations ten feet apart (1 map on 6 sheets; also issued as Atlas DDD, sheets XX
XXV of the Pennsylvania Second Geological Survey's "Report of Progress")
Sheets XXVI
XXIX. Geological and topographical map showing the limestone of Lehigh County including the ranges of brown hematite ore banks with contour-line elevations ten feet apart (1 map on 4 sheets; also issued as Atlas DD, sheets XXVI
XXIX of the Pennsylvania Second Geological Survey's "Report of Progress")
Sheet XXX. Map of the iron ore mines at Ironton, Lehigh County (also issued as Atlas DD, "Ironton mines map" of the Pennsylvania Second Geological Survey's "Report of Progress")
Sheets XXXI
XXXVI. South Mountain map / by A.E. Lehman (1 map on 6 sheets; also issued as Atlas DDDDD, sheets A1
C2 of the Pennsylvania Second Geological Survey's "Report of Progress").