20.O35 [Carrefour Richelieu to Lefebvre Cross Roads, Houthulst Forest] December 18, 1917
Covers an area equivalent to portions of squares O35 and 36 on the corresponding WWI map sheet 20. Negative roll 9B, photo189. Ruins of a chateau are visible at the lower-right of the photo as well as many other smaller structures scattered throughout the photo. Annotations on recto: north arrow pointing to the right. WWI Aerial Photograph Collection: Box 3, Envelope 34.