This final supplement discusses activities proposed for the extended operation of the locks at Sault Ste. Mare, Michigan, beyond 15 December, the historical seasonal closing of the facilities. The proposed extension of operations would allow for continued use of the lock facilities to approximately 8 January. It provides summary of mitigative measures associated with sustaining the navigation season considered to be integral in the social and economic well being of the the Great Lakes Basin regulation and the nation. The extended operation of the federal facilities of the duration anticipated would have no know direct, long-term major adverse environmental effects on the project area. However, sufficient information does not exist to provide confidence that subtle, cumulative impact will not occur resulting in long-term major adverse effects. (Author).