Construction of the St. Lawrence Seaway, 1958

Construction of the Ste. Catherine Lock, 1958
First Flooding of the Lower Beauharnois Lock, 1958

Source: Saint Lawrence Seaway Management Corporation.

The construction of locks was a difficult undertaking as in several places the rock foundation proved to be harder than expected. As the St. Lawrence Seaway was nearing completion in late 1958, locks were being flooded for the first time.