Battle of Hill 70. Situation as reported by Divisions, Midnight, 16-8-1917. Trenches corrected to 20-7-17. 1st Field Survey Coy., R.E. 2458, Canadian Corps Topo Section. Annotation: "Ry Alley" is printed in blue pencil labelling a trench just north of Loos. Map donated by R. James Steel. Location: Research Collections, Fonds: WWI Trench Maps France, Box 14, Envelope 8.