A very rare “Top Secret” map depicting the central Cotentin Peninsula, an area that saw heavy fighting during the advance against Cherbourg in the weeks immediately after D-Day.

This remarkable map depicts a roughly six-by-nine-mile area of the Cotentin Peninsula along the approaches to Cherbourg. That city’s deepwater port facilities were essential to landing the huge volumes of Allied men and materiel necessary for an advance from Normandy into France. Consequently, after landing at Utah Beach on June 6^th, 1944, the U.S. VII Corps advanced west to seal off the peninsula, then pivoted north to roll up the German forces defending Cherbourg.

At the northwest corner of the map is the town of Valognes, which played an important role in the American advance. Lying on the N13 highway, the principal route north from Utah Beach to Cherbourg, it served as a German rear-area anchor and defensive position during the effort to slow VII Corps’ drive up the peninsula. By June 19–20, as the U.S. 4th and 79th Divisions pushed north, Valognes became a near-term objective. The Germans, however, withdrew during the night of June 19–20, leaving the town badly damaged and choked with rubble but no longer strongly defended. Its capture was a sign that the German forward defense had given way, allowing American forces to press rapidly toward Cherbourg. After a campaign of more than three weeks, the German forces defending Cherbourg’s harbor and arsenal surrendered on June 27^th.

The map gave planners and troops on the ground a staggering amount of information about the area. The city itself is shown in great detail, as are roads, towns and villages, with topography indicated by contour lines at 10-meter intervals (Though note 1 in the lower margin warns that “road classification is based on Michelin and other information. It has not been checked on the ground and its reliability is uncertain”, while the contours are to be “accepted with caution”.) There are also distinct symbols for hedges, walls and fences; woods, orchards, and brushwood; vineyards, cemeteries and wells; and windmills and windpumps; among other features of the landscape

Regarding military installations, the information is amazingly detailed: The legend on the back of the map identifies perhaps a hundred distinct symbols, including for example fixed coast guns, fixed coast howitzers, mobile guns or gun-howitzers, mobile howitzers, antiaircraft guns, and anti-tank guns; not to mention machine guns (light/medium, open/in turrets), mortars, anti-aircraft machine guns, and flamethrowers. There are even distinct symbols for barbed and concertina wire, and for single and double fences.

The map bears no imprint, but it was likely the work of Company B of the 660^th Engineers, a photo-mapping unit of 300 men plus officers that arrived in England in September 1942 and was based in a London suburb. Its first, daunting assignment was to prepare maps of northwestern France at a scale of 1:25,000. This essentially meant “producing a completely new map”, as the only existing maps were at a scale of 1:50,000 and based on French sources prepared during the Napoleonic era! (Locke, p. 272) For lack of another option, Company B mapmakers settled on a compromise, using as control points those established during the Napoleonic triangulation, then adding detail from sources ranging from commercial maps by Michelin to photographic data derived from hundreds (thousands?) of RAF reconnaissance flights. (Locke, p. 274)

In all, a rare and richly-informative artifact from one of the most significant and dramatic campaigns in American military history.

References
Not in OCLC or Library Hub Discover. For background on Company B of the 660^th Engineers, see Maj. J. W. Locke, “Military Photogrammetry in Action in Europe” in Photogrammetric Engineering, vol. XII no. 3 (Sept. 1946), pp. 272-81 (accessed online Dec. 2023).