20.O28 [Ptarmigen Junction, Chanzy Corner, and Ferret Junction] December 18, 1917
Covers an area equivalent to portions of squares O28, 33, and 34 on the corresponding WWI map sheet 20. Negative roll 9B, photo 180. Annotations on recto: north arrow pointing to the upper-right. Annotations on the verso: "1st Div. Front - Left." WWI Aerial Photograph Collection: Box 1, Envelope 37.