The Thumb

The Thumb is a region and a peninsula of the U.S. state of Michigan, so named because the Lower Peninsula is shaped like a mitten. The Thumb area is generally considered to be in the Central Michigan region, east of the Flint area and the Tri-Cities and north of Metro Detroit. The region is also branded as the Blue Water Area, and more recently Michigan's Thumb Coast, for tourism purposes.

The counties that constitute the Thumb form the peninsula that stretches northward into Lake Huron and Saginaw Bay. There is no formal list of which counties are part of the Thumb, but virtually all definitions include Huron, Tuscola, and Sanilac counties, and most include Lapeer and St. Clair counties. The population of the Thumb region as of the 2020 census was 370,617.

The Thumb region is very flat with fertile soil, the reason for its historical role as a chiefly agricultural area. Major agricultural products include sugar beets, navy beans, corn, fruits, and fish from Saginaw Bay and Lake Huron. Manufacturing—particularly concerning the automotive industry—is also prevalent in Michigan's Thumb due to the region's proximity to the automotive centers of Detroit and Flint.

The Thumb has many notable businesses, many linked to agriculture.

The I-69 International Trade Corridor is a strategic commercial gateway between the Midwestern United States and Ontario, Canada, with multi-modal transportation infrastructure that offers a wide range of distribution options. The I-69 International Trade Corridor Next Michigan Development Corporation (NMDC) offers economic incentives to growing businesses, both existing and new, that utilize two or more forms of transportation to move their products and are located within the territory of the NMDC. The I-69 International Trade Corridor Next Michigan Development Corporation is the largest in the state of Michigan with 35 municipal partners.

Constituent counties of the trade corridor are: Shiawassee, Genesee, Lapeer, and St. Clair counties.

Some towns, such as Bay Port, Caseville, Harbor Beach, Lakeport, Lexington, Port Austin, Port Hope, Port Huron, Port Sanilac, Sebewaing, and St. Clair enjoy seasonal tourism, due to their locations on Lake Huron, Saginaw Bay, or the St. Clair River. Tourism and farming drive the local economy.

The Tip of The Thumb Heritage Water Trail is a nonprofit citizens organization working with the Huron County Parks to establish and maintain a water trail along Michigan's Lake Huron's shoreline.