20.O36 [Marechal Farm, Houthulst Forest] December 26, 1917, c.4
Covers an area equivalent to portions of squares O36, P31, U6 and V1 on the corresponding WWI map sheet 20. Negative roll 9B, photo number 208. Fourth copy of photo 208 in Box 1, Envelope 64. Annotations on recto: north arrow pointing to the left. "Marechal Fm" printed in white with arrow pointing to its location. Double dashed white line. Several polygons outlined in white dots. 8 white "X"s parallel to road. WWI Aerial Photograph Collection: Box 1, Envelope 67.