[Somme River Region : area of old front lines before 1-17-16 & during Somme Battle 1916]
Series Number Id: GSGS 2742; Sheet number: 62c SW; Edition number: 4b, Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC28; envelope_number: 816, Trenches to 11th March 1918. Base map OS(OB) August 1918. Note change of colour -- enemy trenches in blue, British trenches in red. [All trenches on this sheet in blue]. O/p purple: [5th] FSC 3796 21-6-18. Map showing British organisation on March 21st 1918, o/p green; German organisation to 26-7-18 coloured green.