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.
Economy
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,Saginaw Valley Dry Bean and Sugar Beet Research Farm, Michigan State University. 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.
Industry
The Thumb has many notable businesses, many linked to agriculture. Intertape Polymer Group, Inc. has a major factory in Marysville. Cargill Salt operates a large salt mine and factory in St. Clair. This is the only plant in the U.S. that produces Alberger salt, which is especially prized in the fast food industry because of its higher volume (due to its unique shape) and lower sodium content (for a given volume, not weight). This is part of Michigan's large salt-mining industry. Cooperative Elevator Company has been named the top Michigan Agriculture Exporter by the Michigan Department of Agriculture. Its headquarters are in Pigeon, and it has branch elevators in Deckerville, Akron, Gagetown, Sebewaing, Elkton, and Bad Axe. Detroit Edison is the operator of three power plants in the Thumb area: St. Clair and Belle River Power Plants in East China Township, and Greenwood Energy Center in Greenwood Township. Dow AgroSciences Harbor Beach manufactures agricultural chemicals: weed killer, fungicides, fertilizers and plant nutrients and herbicides. Mueller Industries owns and operates Mueller Brass in Port Huron. Grand Trunk Western Railway has a major rail yard in Port Huron Township. Marysville Hydrocarbons is an ethanol plant in Marysville. SMR Automotive manufactures rear view mirrors at facilities in Port Huron and Marysville.Motherson Sumi Systems Port Huron-based P.J. Wallbank Spring manufactures components for transmissions. Port Huron's industrial park is home to many companies that produce plastic components for vehicles, such as Prism Plastics, Huron Plastics Group, and International Automotive Components. Michigan Ethanol, a partner of Broin Companies, operates a corn ethanol production facility in southwest Caro. Michigan Sugar Company, an agricultural cooperative owned by 1200 farmers, operates four plants in the area. It is the successor to the 100-year-old "Big Chief" and "Pioneer" Sugar companies. Local plants are located in Caro, Sebewaing, Croswell, and headquarters in Bay City. Keihin Michigan Manufacturing operates an auto part manufacturing plant in Capac, they build HVAC and intake manifold assemblies that are used in Honda vehicles. The plant is scheduled to close in 2021. Champion manufactures small and mid size buses at their facility in Lapeer County's Imlay Township. Sensient Technologies Corporation, Harbor Beach, makes food flavors and colors, yeast dehydrated products and vegetable protein extract. Star of the West Milling Co. which has grain elevators in Vassar and Cass City, joined with Eastern Michigan Grain in Emmett. Huron Castings produces shell molded steel castings in Pigeon. Pigeon Telephone Co. has been meeting telecommunications needs of the rural communities it serves since 1908. Agri-Valley Services, more commonly known as AVCI, is an internet service provider based out of Pigeon. Thumb Cellular has been providing rural cellular service to the Thumb area since 1991.
International Trade Corridor 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. Next Michigan Development Corporation
Constituent counties of the trade corridor are: Shiawassee, Genesee, Lapeer, and St. Clair counties.International Trade Corridor
Tourism
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.Tip of The Thumb Heritage Water Trail
Tourism Campaigns Discover the Blue is a promotion by the Blue Water Area Convention and Visitor's Bureau. It is designed to attract visitors to the shoreline of eastern Michigan. Communities participating in Discover the Blue include shorline areas from Algonac in St. Clair County to Port Austin at the tip of the Thumb.
In 2025, the Blue Water Convention and Visitor's bureau rebranded their advertising campaign from Discover the Blue to Discover Michigan's Thumb Coast. The change puts The Thumb first and foremost in the region's branding strategy, due to an already established geographical awareness for the region as compared to Blue Water Area.
Unique to the Thumb Many of the residents commute for work to Metro Detroit, Flint or the Tri-Cities. Incorporated cities with 2,000+ population in the Thumb area are Port Huron, Marysville, Lapeer, St. Clair, Marine City, Algonac, Caro, Imlay City, Bad Axe, Vassar, Sandusky and Croswell. The majority of these cities are in the southern portion of the Thumb.
Unique features in the area include the following: Algonac, known as the Venice of Michigan because of its many canals.Domm, Robert W. (2006). Backroads of Michigan, p. 144. Voyageur Press. Bad Axe was named after a broken axe found lodged in the knot of a tree at the clearing of the settlement's chief crossroads. Bay Port, is the world's largest freshwater fishing port. Harbor Beach is the home of the largest man-made harbor and the Harbor Beach Light. Harvest Wind Farm, an electrical generation project of Exelon Wind and Wolverine Power Supply Cooperative. Harvest II went into commercial operation in November 2012. Huron County Nature Center includes a wilderness arboretum that has been under the care of the Huron County Women's Clubs for more than 50 years. Kernan Memorial Nature Sanctuary is a refuge with of shoreline acquired October 30, 1989 on Lake Huron, in Huron County. On the western coast of Whiskey Harbor, this area is a great place to see migratory birds in early March and November. Kinde was once the bean capital of the world. Michigan Bean soup has been a staple for over a hundred years in the U.S. Senate dining room (Senate bean soup).Michigan Bean Soup recipe and history, the Honorable and Mrs. John D. Rockefeller IV, U.S. Senator. Pigeon is the home of the Cooperative Elevator Company, one of the largest grain elevators in the state. Port Huron is the maritime capital of the Great Lakes, where Lake Huron flows into the St. Clair River. This is the largest city in the Thumb area. It was the boyhood home of Thomas Edison. The Sanilac Petroglyphs were discovered after massive fires swept the Lower Peninsula in 1881. Native Americans created this unusual artwork 300 to 1,000 years ago. The petroglyphs provide a glimpse into the lives of an ancient woodland people who occupied Michigan's Thumb area. Sebewaing is the sugar beet capital of the world, and home to one of the four Michigan Sugar Company factories in the Thumb region. The sugar companies were organized with money from lumber barons such as Rasmus Hanson. St. Clair boasts the world's largest boardwalk along freshwater, the St. Clair River. Turnip Rock, an unusual undercut sea stack at the extreme northern tip of the Thumb. Michigan Underwater Preserves are protected areas of the Great Lakes on Michigan's coast. There are nineteen major shipwrecks in the of the Thumb Area Bottomland Preserve and the Sanilac Shores Underwater Preserve which expands a total of of Lake Huron. Caseville is the home of the annual Cheeseburger in Caseville festival, a hometown festival devoted to Jimmy Buffett's song "Cheeseburger in Paradise".
Traveling around the Thumb A favorite of tourists who visit this area is traveling the Lake Huron and Saginaw Bay shoreline via M-25 (formerly US Highway 25 until 1973). M-25 starts at the end of I-69/I-94 in Port Huron at the foot of the Blue Water Bridge and ends in Bay City. The whole highway is about , and passes through quaint cities and villages. Located along Lake Huron through which M-25 passes are five lighthouses: Fort Gratiot Lighthouse, Port Sanilac lighthouse, Pointe aux Barques Lighthouse, Harbor Beach Light, and the Port Austin Lighthouse.
The Lake Huron Circle Tour is a designated scenic road system connecting all of the Great Lakes and the St. Lawrence River. Many visitors choose to begin the circle tour in Port Huron, from which they can circle Lake Huron. M-25 winds around the Thumb and along Saginaw Bay to Saginaw and Bay City. Lexington and Port Austin feature beaches and boardwalks that are favorites with visitors.
Lighthouse Tour
In order from east to west: Huron Lightship — Lake Huron / St. Clair River — Port Huron Fort Gratiot Light—Lake Huron / St. Clair River—Port Huron Port Sanilac Light—Lake Huron— Port Sanilac—Private White Rock Memorial Light—Lake Huron — White Rock—Private Harbor Beach Light—Lake Huron — Harbor Beach Pointe aux Barques Light—Lake Huron—near Port Hope Port Austin Light—Lake Huron — Port Austin Charity Island Light — Saginaw Bay Saginaw River Light — Saginaw River
Area festivals and events
Antique and Yard Sale Trail 2nd weekend in August, (Algonac to Sebewaing) Art on the River, third week in June, St. Clair. Art on the Avenue, downtown Port Huron, 3rd week in August. around the state. Bay Port Fish Sandwich Festival (Bay Port) Blue Water Ramble (St. Clair) Annual International Bicycling Event along the St. Clair River in Michigan and Ontario, Canada, involving two ferry boat crossings, first weekend in October. Boat Night & Port Huron to Mackinac Boat Race (Port Huron to Mackinac Island) Detroit News Cheeseburger in Caseville Festival (Caseville)Cheesburger in Caseville at Pure Michigan.Campbell, Ron. August 13, 2010 Cheeseburger in Caseville festival turns town into 'Fun, wacky, tasteful and tacky' place Bay City Times. Croswell Agricultural Society Fair (Croswell) celebrating its 125th year in 2009 Croswell Swinging Bridge Festival (Croswell) Feast of the Sainte Claire sponsored by the Port Huron Museum of Arts and History, a large living reenactment of 18th century life—Memorial Day weekend, (Port Huron). Harbor Beach Maritime Festival(Harbor Beach) Huron County Fair (Bad Axe) Michigan Bean Festival Labor Day weekend (Fairgrove) Farmer's Festival (Pigeon) Michigan Sugar Festival (Sebewaing)