Scientists have divided Michigan into four major regions: southern Lower Peninsula, northern Lower Peninsula, eastern Upper Peninsula, and the western Upper Peninsula. Following is a description of each of these regions. 

Note: Pre-settlement refers to how Michigan looked according to surveys completed around 1800, prior to large-scale Euro-American settlement of the region.

Southern Lower Peninsula. The southern Lower Peninsula is characterized by a warmer climate and a longer growing season than elsewhere in the state. This region receives more precipitation in spring than in fall, with total amounts more variable than other regions of Michigan. The geology of this region is soft limestone covered by glacial deposits. The topography has an elevation of less than 1,200 feet and features low, flat plains with hilly areas in the southwest and along a line from Hillsdale to Lapeer. Predominant soilsinclude loams and clays in variations of dry or wet environments, and sandy soils near Lake Michigan and near hilly areas.

Prior to Euro-American settlement in the southern Lower Peninsula, oak-hickory forest, beechsugarmaple forest, oak-savanna, wetlands, and deciduous swamps were the dominant land types. Today, agriculture, homes, businesses, and roads have replaced most of these original land types. Scattered woodlots remain mainly in areas with moist or wet soils, which are harder to drain and convert to other land uses. In many areas, over half of the pre-settlement wetlands have been drained, and only a few tiny isolated oak-savannas remain.

Northern Lower Peninsula. Even though the geology of this northern area is similar to southern Michigan, with its soft limestone bedrock covered by glacial deposits, the climate, soils, and cover types begin to change north of a line from Muskegon to just north of Bay City. This line marks a transition or “tension zone” that separates the Lower Peninsula into north and south ecosystems. The topography of the northern Lower Peninsula is mainly hilly with elevations as high as 1,600 feet, but features relatively flat areas in the central portion and along the eastern Lake Huron shoreline. The climate of this region is cooler and more variable than in southern Michigan.

Prior to European settlement in the northern Lower Peninsula, the major landcover types were northern hardwoods, oak-pine barrens, pine forests, and conifer swamps. Today, this regional landscape is still covered with forest, although in some areas agriculture and homes have replaced the forest. Also, because of past and present timber harvest methods, there has been a rapid increase in aspen across the region. There has also been a conversion of conifer swamps into swamp brushlands.

Eastern Upper Peninsula. This area is characterized by limestone and dolomite bedrock, which is softer than the underlying deposits of the western Upper Peninsula. The overall flat eastern end is characterized by elevations under 800 feet and climates that are greatly influenced by the Great Lakes, causing warmer winters and cooler summers than other areas of the same latitude. The frost-free period and growing season are short compared to southern Michigan. Major soil types in this region are wet sands, clays, and organic soils.

Prior to European settlement, the region was covered with northern hardwood forests, conifers, conifer-hardwood swamps, aspen-birch, peatlands, and vast marshes along the Great Lakes. Today, many of the Great Lakes’ marshes have been lost, some forest areas have been converted to agriculture, and areas once supporting mixed pine have been converted to red pine plantations.