The Corps' Supplemental Reconnaissance Report now replaces the GLSLS study.

The Detroit District of the Army Corps of Engineers has completed, as of February 2010, a Supplemental Reconnaissance Report for the Great lakes Navigation System. This Report was developed to analyze the current infrastructure and economic viability of the Great Lakes commercial shipping industry, and what, if any, adjustments to the U.S. portion of the system would help it to operate more efficiently. This Corps Supplemental Reconnaisance Report used much of the research contained in the concurrently-developed bi-national Great Lakes St. Lawrence Seaway Study, completed in the fall of 2007, to determine the U.S. federal interest in maintaining the Great Lakes navigation system. The Supplemental Reconnaissance Report includes the bi-national GLSLS study in Appendix B.