Sault Sainte Marie Locks of major importance for American arms production according to the U.S. Joint Intelligence Committee. Daily summary dated 20 February 1942

An item reported that according to a J.I.C. comment the American production of arms would be in fact ended if the Sault Sainte Marie or SOO Canal locks (1) would be destroyed. One real scenario was an attack by paratroopers and airborne engineer demolition crews landing on the ice above and below the locks. The solution was a well-coordinated defence consisting of at least ground troops, interceptor pursuit, aircraft warning net and a DERAX Station.

Note

1. These locks located on the St. Marys River connected Lake Superior, the lower Great Lakes and the St. Lawrence Seaway for cargo ships.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. MR0423. U.S. Joint Intelligence Committee. Daily summary No. 72 dated 20 February 1942