The Lower Peninsula of Michigan – also known as Lower Michigan – is the larger, southern and less elevated of the two major landmasses that make up the U.S. state of Michigan; the other being the Upper Peninsula, which is separated by the Straits of Mackinac. It is surrounded by water on all sides except its southern border, which it shares with Indiana and Ohio. Although the Upper Peninsula is commonly referred to as "the U.P.", it is uncommon for the Lower Peninsula to be called "the L.P."
Lake Huron is one of the five Great Lakes of North America. Hydrologically, it comprises the easterly portion of Lake Michigan–Huron, having the same surface elevation as Lake Michigan, to which it is connected by the 5-mile-wide (8.0 km), 20-fathom-deep Straits of Mackinac. It is shared on the north and east by the Canadian province of Ontario and on the south and west by the U.S. state of Michigan. The name of the lake is derived from early French explorers who named it for the indigenous people they knew as Huron (Wyandot) inhabiting the region.
Lake Agassiz was a large proglacial lake that existed in central North America during late Pleistocene, fed by meltwater from the retreating Laurentide Ice Sheet at the end of the last glacial period. At its peak, the lake's area was larger than all of the modern Great Lakes combined.
Lake St. Clair is a freshwater lake that lies between the Canadian province of Ontario and the U.S. state of Michigan. It was named in 1679 by French Catholic explorers after Saint Clare of Assisi, on whose feast day they first saw the lake.
Lake Michigan–Huron is the body of water combining both Lake Michigan and Lake Huron, which are joined through the 5-mile-wide (8.0 km), 295-foot-deep (90 m), open-water Straits of Mackinac. Huron and Michigan are hydrologically a single lake because the flow of water through the straits keeps their water levels in overall equilibrium. Although the flow is generally eastward, the water moves in either direction depending on local conditions. Combined, Lake Michigan–Huron is the largest freshwater lake by area in the world. Lake Superior is larger than either individually, so it is counted as the largest of the Great Lakes when Lake Michigan and Lake Huron are considered separately.
Lake Algonquin was a prehistoric proglacial lake that existed in east-central North America at the time of the last ice age. Parts of the former lake are now Lake Huron, Georgian Bay, Lake Superior, Lake Michigan, Lake Nipigon, and Lake Nipissing.
Lake Duluth was a proglacial lake that formed in the Lake Superior drainage basin as the Laurentide Ice Sheet retreated. The oldest existing shorelines were formed after retreat from the Greatlakean advance, sometime around 11,000 years B.P. Lake Duluth formed at the western end of the Lake Superior basin. Lake Duluth overflowed south through outlets in Minnesota and Wisconsin at an elevation of around 331 m above sea level.
Early Lake Erie was a prehistoric proglacial lake that existed at the end of the last ice age approximately 13,000 years ago. The early Erie fed waters to Glacial Lake Iroquois.
Lake Chicago was a prehistoric proglacial lake that is the ancestor of what is now known as Lake Michigan, one of North America's five Great Lakes. Formed about 13,000 years ago and fed by retreating glaciers, it drained south through the Chicago Outlet River.
Lake Maumee was a proglacial lake and an ancestor of present-day Lake Erie. It formed about 17,500 calendar years, or 14,000 Radiocarbon Years Before Present (RCYBP) as the Huron-Erie Lobe of the Laurentide Ice Sheet retreated at the end of the Wisconsin glaciation. As water levels continued to rise the lake evolved into Lake Arkona and then Lake Whittlesey.
The Toleston Shoreline is the third ancient shoreline of the precursor to Lake Michigan, Lake Chicago. It takes its name from the village of Tolleston, now a portion of Gary, Indiana. The shoreline formed when Lake Chicago was high enough to drain through the Chicago outlet into the Des Plaines River. The beach is 18 to 25 feet above the level of Lake Michigan. The Indiana segment and the Illinois segment, north to Evanston are still visible. North of Evanston and Michigan City, Indiana, the beach has been eroded by later ice movement or shoreline wave action.
Lake Kankakee formed 14,000 years before present (YBP) in the valley of the Kankakee River. It developed from the outwash of the Michigan Lobe, Saginaw Lobe, and the Huron-Erie Lobe of the Wisconsin glaciation. These three ice sheets formed a basin across Northwestern Indiana. It was a time when the glaciers were receding, but had stopped for a thousand years in these locations. The lake drained about 13,000 YBP, until reaching the level of the Momence Ledge. The outcropping of limestone created an artificial base level, holding water throughout the upper basin, creating the Grand Kankakee Marsh.
Lake Chippewa was a prehistoric proglacial lake. The basin is now Lake Michigan. It formed about 10,600 years before present (YBP). The lake occupied the depression left by the Michigan Lobe of the Laurentide Ice Sheet.
Lake Saginaw occupied the basin of Saginaw Bay. There were two periods when it was an independent lake, not associated with a larger body of water in the Huron basin. The first Lake Saginaw was a contemporary of the last stages of Lake Maumee. When the ice border opened allowing these two lakes to become one, it entered the period of Lake Arkona. Then, the ice advanced, closing the link forming the second Lake Saginaw. This was during the time of Lake Whittlesey. When the ice margin retreated northward for the last time, it became the western bay of Lake Wayne and then of Lake Warren and Lake Lundy. During its periods as an independent lake, its outlet was west through Grand River channel.
Lake Whittlesey was a proglacial lake that was an ancestor of present-day Lake Erie. It formed about 14,000 years ago. As the Erie Lobe of the Wisconsin Glacier retreated at the end of the last ice age, it left melt-water in a previously-existing depression area that was the valley of an eastward-flowing river known as the Erigan River that probably emptied into the Atlantic Ocean following the route of today's Saint Lawrence River. The lake stood at 735 feet (224 m) to 740 feet (230 m) above sea level. The remanent beach is not horizontal as there is a ‘hinge line’ southwest of a line from Ashtabula, Ohio, through the middle part of Lake St. Clair. The hinge line is where the horizontal beaches of the lake have been warped upwards towards the north by the isostatic rebound as the weight of the ice sheet was removed from the land. The rise is 60 feet (18 m) north into Michigan and the Ubly outlet. The current altitude of the outlet is 800 feet (240 m) above sea level. Where the outlet entered the Second Lake Saginaw at Cass City the elevation is 740 feet (230 m) above sea level. The Lake Whittlesey beach called the Belmore Beach and is a gravel ridge 10 feet (3.0 m) to 15 feet (4.6 m) high and one-eighth mile wide. Lake Whittlesey was maintained at the level of the Ubly outlet only until the ice melted back on the "Thumb" far enough to open a lower outlet. This ice recession went far enough to allow the lake to drop about 20 feet (6.1 m) below the lowest of the Arkona beaches to Lake Warren levels.
Lake Arkona was a stage of the lake waters in the Huron-Erie-Ontario basin following the end of the Lake Maumee levels and before the Lake Whittlesey stages, named for Arkona, Ontario, about 50 miles (80 km) east of Sarnia.
Lake Warren was a proglacial lake that formed in the Lake Erie basin around 12,700 years before present (YBP) when Lake Whittlesey dropped in elevation. Lake Warren is divided into three stages: Warren I 690 feet (210 m), Warren II 680 feet (210 m), and Warren III 675 feet (206 m), each defined by the relative elevation above sea level.
Lake Wayne formed in the Lake Erie and Lake St. Clair basins around 12,500 years before present (YBP) when Lake Arkona dropped in elevation. About 20 feet (6.1 m) below the Lake Warren beaches it was early described as a lower Lake Warren level. Based on work in Wayne County, near the village of Wayne evidence was found that Lake Wayne succeeded Lake Whittlesey and preceded Lake Warren. From the Saginaw Basin the lake did not discharge water through Grand River but eastward along the edge of the ice sheet to Syracuse, New York, thence into the Mohawk valley. This shift in outlets warranted a separate from Lake Warren. The Wayne beach lies but a short distance inside the limits of the Warren beach. Its character is not greatly different when taken throughout its length in Michigan, Ohio, Pennsylvania and New York. At the type locality in Wayne County, Michigan, it is a sandy ridge, but farther north, and to the east through Ohio it is gravel. The results of the isostatic rebound area similar to the Lake Warren beaches.
Anchor Bay is a freshwater bay forming the northern region of Lake St. Clair in the U.S. state of Michigan. It generally encompasses the waters north of a line between Huron Point and the Middle Channel of the St. Clair River. It covers over 90 square miles (230 km2) and a depth of from 1 to 11 feet, which is unusually shallow for its immense size.
