Gary Lake

Gary Lake (also sometimes seen as Lake Gary) is a glacial lake that existed in the Lake Superior basin during the last ice age, approximately 10,000 to 12,000 years ago. It was formed as the Laurentide Ice Sheet retreated, leaving behind meltwater that was impounded by the remaining ice and higher terrain.

Lake Gary was significantly larger and deeper than the present-day Lake Superior. Its boundaries shifted as the ice sheet continued to recede and new outlets opened. It drained through several different outlets, including routes to the Mississippi River system and the Ottawa River system. The changing drainage patterns had a profound impact on the landscape, carving new channels and shaping the surrounding terrain.

Evidence for Lake Gary includes raised beaches, shorelines, and lacustrine sediments found along the present shores of Lake Superior and inland areas. These geological features provide valuable information about the lake's extent, depth, and drainage history. Studies of these features help geologists understand the dynamics of the ice sheet retreat and the evolution of the Great Lakes system. The subsequent lower water levels and opening of the St. Lawrence River led to the formation of the modern Lake Superior.