stage for the next major proglacial lakes in the Lake Michigan basin as Lake Algonquin and then Nipissing Great Lakes. Size Extending somewhat further south, west and east than Lake Michigan, Lake Chicago extended west to present day La Grange, Illinois and south beyond Homewood and Lansing, Illinois, completely covering what is now Northwest Indiana, including the cities of Hammond and Gary, Indiana. As the Wisconsin Glacier continued to retreat, it created new outlets for the water in Lake Chicago, including Niagara Falls, and the St. Lawrence River. As these outlets were developed, a partial lake capture occurred and the water level in Lake Chicago began to drop in three observable stages of 15 to 20 feet (5–6 m) each. Eventually even the outlet to the southwest dried up, and the Des Plaines River overflowed into the basin that became Lake Michigan. Outlet and beaches As the Michigan Lobe of the Labradorean Ice Cap retreated northward, the area of Lake Chicago increased. Lake Chicago’s initial outlet was to the southwest through the Des Plaines River valley, thence down the Illinois River to the Gulf of Mexico. The highest beach is the Glenwood Shoreline, which is to above the level of Lake Michigan. There are two additional beaches formed when the Des Plaines outlet was abandoned for other outlets to the north and east: the Calumet Shoreline, about to above the current lake, and the Tolleston Beach to above Lake Michigan. The name Lake Chicago is used for the lake when it drains through the Des Plaines outlet. The Calumet and Tolleston Beach lake is Lake Algonquin. The outlet channel is more than wide and cuts through glacial deposits. Near the head of the channel, rock layers have been cut through. It is probable that the distinct beaches from Lake Chicago are the result of these rock layers giving way rapidly, dropping the lake level from higher to lower levels. After each stage, the next barrier remained solid, holding the lake stable and creating distinct beaches. If the outlet were formed by a steady erosion of the barrier, it would have been less likely that the well-defined beaches would have been created. Along the eastern shore of Lake Michigan, the beaches of Lake Chicago have been destroyed by erosion, except the highest beach, much of which has also been destroyed. The best remaining segments are along the southern tip of Lake