Series consists of First World War trench series maps held by the National Archives of Canada. It lists six different series published by the British, French, and German governments. In all cases, information on trenches and enemy organization was overprinted onto existing topographic base maps. The base maps used by the British Expeditionary Force are listed in another section of this guide and carry the same GSGS series number as the trench overprints. The edition statements on the British trench maps distinguished between the topographic base map and the trench overprint. Updates to the topographic map were given new edition numbers, while updates to the trench overprint were distinguished by a new letter. When a new base map was issued, the first trench overprint using the new edition was always given the suffix "A". For example, edition "4C" meant that the trench overprint was the third overprint to be issued on the fourth edition of the base map. Some edition statements on British trench maps also included the term "local". This term was introduced to distinguish between editions that had been published locally in France and those that had been published in England. However, as the war progressed and map production in France became more common, the distinction was eventually abandoned. (the preceeding text is adapted from Jeffrey Murray's "Guide to Maps of the First World War")
The series are ordered by scale, starting with the largest scales first.
The series is broken down into the following sub-series:
Sub-series 2.1 [Belgium and France 1:10,000 Trench Map.] GSGS 3062. Index Map
Sub-series 2.2 [Belgium and France 1:20,000 Trench Map.] GSGS 2742. Index Map
Sub-series 2.3 [France - Groupe des Canevas de Tir, Trench Map]. 1:20,000.
Sub-series 2.4 Zusammendruck 1:25,000 [Trench Map].
Sub-series 2.5 Belgium and France 1:40,000 [Trench Map]. GSGS 2743. Index Map
Sub-series 2.6 Zusammendruck 1:50,000 [Trench Map].