Waterfall over Benwood L., ravine tributary to Meigs Ck. [creek], Washington Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
Coal pit & F.G.C. [Frederick Gardner Clapp], Greene Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Ni...
C. of Washington, Pa. [Pennsylvania], from south. (1904)GrayscaleClapp Nitrate Negative, Box 1
F.G. [Frederick Gardner] Clapp and Allegheny R. [river], nr [near] Oakmont, Pa. [Pennsylvania]. (ca....
Cultivated hillside, Washington Co., Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Terrace of Waynesburg S.S., Rich hill two, Greene Co., Pennsylvania. U.S. - disc. (1904)GrayscaleCla...
Reservoir No. 4, near Washington, Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Valley of ten mile creek, near Ten-Mile, Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Washington field, Washington Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
Susquehanna R. [river], Curwensville, Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box...
Washington Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
Brobaker Run, Cambria Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
W. [water] flowing from well of Pet. Rec. Co., Bradford, Pa. [Pennsylvania]. (1932)GrayscaleClapp Ni...
Clearfield Ck. [creek] nr [near] Ashville, Cambria Co., Pennsylvania. (1904)GrayscaleClapp Nitrate N...
Burning gas well, Washington Co., Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Little Yellow Creek, Cambria Co., Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Coal pit & F.G.C. [Frederick Gardner Clapp], Greene Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Ni...
C. of Washington, Pa. [Pennsylvania], from south. (1904)GrayscaleClapp Nitrate Negative, Box 1
F.G. [Frederick Gardner] Clapp and Allegheny R. [river], nr [near] Oakmont, Pa. [Pennsylvania]. (ca....
Cultivated hillside, Washington Co., Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Terrace of Waynesburg S.S., Rich hill two, Greene Co., Pennsylvania. U.S. - disc. (1904)GrayscaleCla...
Reservoir No. 4, near Washington, Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Valley of ten mile creek, near Ten-Mile, Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Washington field, Washington Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
Susquehanna R. [river], Curwensville, Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box...
Washington Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
Brobaker Run, Cambria Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Nitrate Negative, Box 1
W. [water] flowing from well of Pet. Rec. Co., Bradford, Pa. [Pennsylvania]. (1932)GrayscaleClapp Ni...
Clearfield Ck. [creek] nr [near] Ashville, Cambria Co., Pennsylvania. (1904)GrayscaleClapp Nitrate N...
Burning gas well, Washington Co., Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Little Yellow Creek, Cambria Co., Pennsylvania. (1904)GrayscaleClapp Nitrate Negative, Box 1
Coal pit & F.G.C. [Frederick Gardner Clapp], Greene Co., Pa. [Pennsylvania]. (1904)GrayscaleClapp Ni...
C. of Washington, Pa. [Pennsylvania], from south. (1904)GrayscaleClapp Nitrate Negative, Box 1
F.G. [Frederick Gardner] Clapp and Allegheny R. [river], nr [near] Oakmont, Pa. [Pennsylvania]. (ca....