Things to Do in Michigan’s Thumb: Coast, Lighthouses & More

Michigan’s Thumb is the part of the state that most visitors drive past on the way somewhere else, which is exactly why it is worth slowing down for. Lake Huron and Saginaw Bay wrap three sides of the peninsula, freighters slide past the St. Clair River shoreline close enough to read their names, five historic lighthouses line the scenic M-25 shore road, and the tip of the Thumb has a designated dark sky preserve. Inland, you will find farm country, a giant octagon barn and Michigan’s largest collection of Native American rock carvings.

Use this guide as your starting point. It explains how we define the region, compares ten towns side by side, and highlights what each does best. It also covers the inland sights that make a good detour, a park pass decoder, sample itineraries, seasons, getting around and safety basics. Each town section links to our full guide for that town.

What Counts as the Thumb?

The Thumb has no formal list of counties, but virtually all definitions include Huron, Tuscola and Sanilac counties, and most also include Lapeer and St. Clair counties. We use all five. The tourism brands you will see here, “Blue Water Area” along the St. Clair River and “Michigan’s Thumb Coast” along Lake Huron, describe the same shoreline.

A note on neighbors: Wikipedia describes the Thumb as a sub-region of Mid Michigan, but we treat it as its own destination because the trip is different, a shoreline drive with lighthouses and harbor towns. Metro Detroit is covered in our Southeast Michigan guide. Our Mid-Michigan guide picks up to the west and south around Saginaw Bay.

The Thumb at a Glance

Which Thumb Town Is Right for You?

Each town on this shoreline has its own personality. Use this table to match the trip you want with the right base.

Explore the Thumb Town by Town

We start at the southern end of the coast and work north along M-25, then cover the inland gateway of Lapeer.

Algonac: Freighters, Boats and a Delta Island

Algonac sits where the St. Clair River spills into Lake St. Clair. Algonac State Park is best known for its up-close views of freighters traveling the river, with about half a mile of river frontage, a campground and rare lake-plain prairie and oak savanna habitat. A boardwalk at Algonac Waterfront Park runs along the river in town, and a ferry from Clay Township carries visitors to Harsens Island, a delta island with the St. Clair Flats Wildlife Area and its own water trail.

Good to know: Algonac State Park requires a Recreation Passport for vehicle entry. Read our Algonac guide →

Marine City: Shipbuilding Heritage on the River

Marine City, like Port Huron, became a major shipbuilding center in the 1800s, and a state historical marker near Algonac notes that vessels built here by the Ward brothers carried immigrants up the river on their way west. Today, the Marine City Riverwalk and riverfront parks make a good place to watch passing freighters, and the Marine City Pride & Heritage Museum covers the city’s past. Bridge to Bay Trail routes pass through town, including a six-mile ride toward East China.

Good to know: Marine City and Algonac both have state boating access sites. Read our Marine City guide →

St. Clair: A Walkable Riverfront

St. Clair is a town of tree-lined streets, boat harbors, boutiques and cafes on the St. Clair River. Its Palmer Park is billed by the Bridge to Bay Trail as home to the world’s longest freshwater boardwalk, and a 16-mile ride follows the river from St. Clair to Marysville. Freighter-watching is one of the main draws, and the Blue Water Area visitors bureau lists St. Clair as one of the best vantage points on the river.

Good to know: St. Clair is easy to combine with Marine City and Port Huron in a single river day. Read our St. Clair guide →

Port Huron: Lighthouse, Lightship and the Border

Port Huron is the Thumb’s largest city and sits at the foot of the Blue Water Bridge, an international crossing to Sarnia, Ontario. Port Huron Museum operates four sites: the Thomas Edison Depot Museum, the Huron Lightship, the Carnegie Center and the Fort Gratiot Light, which the visitors bureau calls Michigan’s oldest working lighthouse. The depot is an 1858 Grand Trunk building where a young Edison worked selling newspapers and candy to train passengers. The Huron Lightship, built in 1920, was the last lightship afloat on the Great Lakes and is a National Historic Landmark.

The Blue Water River Walk runs nearly a mile along the St. Clair River, with a fishing pier and a close-up view of passing freighters, and it connects to the Bridge to Bay Trail. Many travelers begin the 1,059-mile Lake Huron Circle Tour here.

Good to know: Amtrak’s Blue Water line connects Port Huron with Chicago. The Edison Depot Museum has seasonal hours, so check before you go. Read our Port Huron guide →

Lexington: A Classic Harbor Village

North of Port Huron, M-25 follows the Lake Huron shoreline to Lexington, a harbor village with a state harbor, a beach and a boardwalk. Its Village Theatre and annual Thumbfest keep the calendar busy in summer. Offshore, the Sanilac Shores Underwater Preserve stretches from near Lexington to Forestville and protects many Great Lakes shipwrecks for divers. The historic homes and civic buildings downtown are on the Michigan State Historic Sites list.

Good to know: Lakeport State Park, just north of Port Huron, is the southernmost of the Thumb’s Lake Huron state parks, so it makes a good stop on the way. Downtown Lexington’s park is my families favorite spot on Lake Huron. Read our Lexington guide →

Port Sanilac: A Small Historic Harbor Town

Port Sanilac packs a lot into a small footprint: a white brick lighthouse built in 1886 on a residential street, the Barn Theatre, a municipal harbor and a beach. The Sanilac County Historic Village & Museum preserves the area’s past. A roadside marker about 1.5 miles south of town commemorates the Great Lakes Storm of 1913. Farm stops nearby include a u-pick lavender farm.

Good to know: The Port Sanilac lighthouse is a private residence, so view it from the street. Read our Port Sanilac guide →

Harbor Beach: The Man-Made Harbor

Harbor Beach is known for its harbor, which Michigan State University Extension describes as the world’s largest man-made freshwater harbor, and for the Harbor Beach Light at its mouth. The town was the birthplace of Frank Murphy, born here in 1890, who served as a U.S. Supreme Court justice; the Justice Frank Murphy Museum tells his story. The harbor, beach and breakwall make for a quiet stop on the Thumb Coast.

Good to know: Harbor Beach sits between Port Sanilac and Port Austin, roughly halfway up the Lake Huron shore. Read our Harbor Beach guide →

Port Austin: The Tip of the Thumb

Port Austin sits at the very tip of the Thumb and is the best base for outdoor travelers. Port Crescent State Park, just outside town, has three miles of sandy Lake Huron shoreline and a designated dark sky preserve, with an observation platform popular for stargazing. Nearby, Turnip Rock, a striking rock formation rising from Lake Huron, is reached on a roughly 7-mile round trip by kayak or canoe, or by hiking the Point aux Barques trail. The land around it is privately owned, so be respectful.

The Port Austin Reef Light stands offshore and is visible from the beach on clear days, and the Pointe aux Barques Lighthouse and its maritime museum are a short drive east. Port Austin also hosts a popular Saturday farmers market.

Good to know: Port Crescent State Park requires a Recreation Passport. Local outfitters rent kayaks for Turnip Rock. Read our Port Austin guide →

Caseville: Saginaw Bay Beaches

On the Saginaw Bay side of the tip, Caseville is a beach town where much of Huron County’s summer tourism concentrates, alongside Port Austin. Albert E. Sleeper State Park, about five miles away, covers 723 acres of forest, wetlands, forested dunes and half a mile of sandy shoreline. The park is named for the governor who signed the law creating Michigan’s state park system, and it also has a trailhead for the Point aux Barques hike to Turnip Rock.

Good to know: The state park’s day-use area is across M-25 from the campground, and a Recreation Passport is required. Read our Caseville guide →

Lapeer: The Courthouse Town and Gateway to the Thumb

Lapeer sits on I-69 on the western edge of the Thumb and works as a gateway from Metro Detroit and Flint. Its downtown is anchored by the Lapeer County Courthouse, built in 1846 and described as the oldest continuously active courthouse in Michigan and one of the ten oldest in the country. Just south of the city, Metamora-Hadley State Recreation Area centers on an inland lake with swimming beaches, a boat launch, a campground and trails.

Good to know: Lapeer hosts its annual Lapeer Days festival each August. There are also many u-pick blueberry farms in the area. Read our Lapeer guide →

Inland Thumb: Rock Carvings, a Giant Barn and Farm Country

Sanilac Petroglyphs Historic State Park

Near Cass City, Sanilac Petroglyphs Historic State Park protects Michigan’s largest known collection of early Native American carvings. The Anishinaabe name for them, Ezhibiigaadek Asin, means “written on stone.” The 240-acre park is co-managed by the Michigan DNR, the Michigan History Center and the Saginaw Chippewa Indian Tribe of Michigan, which the state describes as the first state-tribal co-management of a Michigan state park. A quarter-mile accessible trail leads to the viewing enclosure, and a one-mile loop trail passes the remains of a 19th-century logging camp. Allow about two hours.

The Michigan History Center says parking and admission are free. Guided tours of the petroglyphs run Wednesday through Sunday during the summer season, so check the dates before you go. Read our Sanilac Petroglyphs guide →

Thumb Octagon Barn

In Tuscola County near Gagetown, the Thumb Octagon Barn Agricultural Museum is described as the largest timber-frame octagon barn in the country, 102 feet across and 70 feet high. Construction began in 1924, and its vast open interior earned it the nickname “air castle.” A volunteer group saved it from demolition and now runs it as an educational site, including a harvest festival each autumn. Read our Octagon Barn guide →

Farm Country and Small-Town Theaters

Agriculture drives the Thumb’s economy, and Sebewaing is known as the sugar beet capital of the world, home to one of the Michigan Sugar Company’s factories. Wind turbines dot the farmland near Forestville and elsewhere, and a drive past them is a popular detour. In Tuscola County, the historic Vassar Theater, Cass Theatre in Cass City and Strand Theatre in Caro still serve their communities.

Thumb Parks and Passes, Decoded

Most of the Thumb’s best beaches and trails are in Michigan state parks, but some are county or local parks with their own rules. Use this table as a starting point.

About the Recreation Passport: It grants vehicle entry to all 103 Michigan state parks and recreation areas. For 2026, the Michigan DNR lists the passport at $15 for Michigan-registered vehicles when added during license plate renewal. Out-of-state vehicles pay $42 for an annual pass or $12 for a day pass. You do not need one if you arrive on foot or by bicycle. Prices can change, so confirm on the Michigan DNR website.

Four Sample Thumb Itineraries

These routes are built around the places above. Check hours and seasonal schedules before you go.

The St. Clair River Freighter Weekend (Algonac to Port Huron)

1. Day 1: Start at Algonac State Park for freighter watching, then follow the river north through Marine City and St. Clair, with a walk on each riverwalk.
2. Day 2: Spend the day in Port Huron: the Fort Gratiot Light, Huron Lightship and Edison Depot Museum, then the Blue Water River Walk.

The M-25 Coast Drive (Port Huron to Port Austin)

1. Day 1: Leave Port Huron and drive north on M-25 through Lexington and Port Sanilac, with stops at the harbors and the Port Sanilac Lighthouse.
2. Day 2: Continue to Harbor Beach for the harbor and the Frank Murphy museum, then on to Port Austin.
3. Day 3: Spend the morning on the water or the trail to Turnip Rock, then stargaze at Port Crescent State Park after dark.

Tip of the Thumb (Port Austin and Caseville)

1. Day 1: Paddle to Turnip Rock in the morning, then visit the Pointe aux Barques Lighthouse and its maritime museum.
2. Day 2: Spend the day at Port Crescent State Park or Albert E. Sleeper State Park, then browse Port Austin’s Saturday farmers market if the timing works.

Inland Oddities (Petroglyphs and Octagon Barn)

1. Morning: Visit Sanilac Petroglyphs Historic State Park near Cass City and hike the one-mile loop.
2. Afternoon: Drive to the Thumb Octagon Barn near Gagetown. Stop in Caro or Cass City to see a historic theater.

If It Rains

The Thumb’s indoor options include the Port Huron Museum sites, the Frank Murphy museum in Harbor Beach, the Sanilac County Historic Village & Museum in Port Sanilac, the Pointe aux Barques Lighthouse maritime museum, the Pride & Heritage Museum in Marine City and the Thumb’s historic theaters.

When to Go: A Season-by-Season Planner

Getting to and Around the Thumb

• By road: I-94 and I-69 meet at Port Huron, where M-25 begins at the foot of the Blue Water Bridge. M-25 winds around the Thumb and along Saginaw Bay to Bay City, passing the Thumb’s five Lake Huron lighthouses. M-53 runs north-south up the middle of the peninsula, and I-69 crosses the southern Thumb through Lapeer.
• By train: Amtrak’s Blue Water line runs between Port Huron and Chicago. Local travel from the station is easiest with a car.
• Across the border: The Blue Water Bridge links Port Huron with Sarnia, Ontario. Check current U.S. and Canadian border requirements before you go, and bring a valid passport or other approved travel document.
• Scenic route: The Lake Huron Circle Tour, a 1,059-mile route around the lake, can begin in Port Huron.

Beach and Water Safety on Lake Huron

Lake Huron is cold, deep and changeable. The National Weather Service and Michigan Sea Grant warn that rip currents and structural currents near piers and breakwalls can be dangerous on the Great Lakes, so keep these basics in mind:

• Check the National Weather Service’s Great Lakes beach hazard forecast and local flag warnings before you swim.
• Stay out of the water around piers, breakwalls and harbor mouths, and avoid walking on piers when the surf is high.
• If you paddle to Turnip Rock, check the wind and wave forecast, wear a life jacket and carry a way to call for help.
• If you are caught in a rip current, do not fight it. Swim parallel to the shore until you are free.

The Thumb FAQ

What counts as the Thumb?

There is no formal list of counties. Virtually all definitions include Huron, Tuscola and Sanilac counties, and most include Lapeer and St. Clair counties. We include all five.

What are the best things to do in Michigan’s Thumb?

Popular picks include Port Huron’s lighthouse and lightship, freighter watching on the St. Clair River, the M-25 coast drive, Turnip Rock, Port Crescent State Park’s dark skies, the Sanilac Petroglyphs and the Thumb Octagon Barn.

How do I get to Turnip Rock?

Turnip Rock is reached by water or on foot. The Michigan DNR describes a 7-mile round trip along the Point aux Barques trail, and the trip is also commonly done by kayak or canoe from Port Austin. The land around it is privately owned.

How many lighthouses are on the Thumb Coast?

Five historic lighthouses line M-25: Fort Gratiot, Port Sanilac, Pointe aux Barques, Harbor Beach and Port Austin. Some are private or open only seasonally.

Do I need a Recreation Passport for Thumb state parks?

Yes, for vehicle entry at most state parks, including Port Crescent, Albert E. Sleeper, Algonac and Lakeport. The Michigan History Center says the Sanilac Petroglyphs charge no admission or parking fee.

Can I cross into Canada from the Thumb?

Yes. The Blue Water Bridge at Port Huron connects to Sarnia, Ontario. You need valid travel documents such as a passport, and requirements change, so check official border guidance first.

Can I visit the Thumb without a car?

Partly. Amtrak’s Blue Water serves Port Huron, but the shoreline, parks and inland sights are much easier to reach by car.

When is the best time to visit the Thumb?

Summer is best for beaches and harbors, while fall suits dark sky viewing, harvest events and quieter roads. Spring and winter are quiet, with many seasonal attractions closed.

Keep Planning

• Southeast Michigan: Detroit, Ann Arbor and Beyond
• Mid-Michigan Travel Guide
• Northern Michigan Travel Guide
• All Michigan Destinations

Sources and Further Reading

We build these guides from official and primary sources wherever possible. Details like hours, prices and festival dates change, so confirm them with the sources below before you go.

• Michigan DNR: Recreation Passport
• Michigan DNR: Algonac State Park
• Michigan DNR: Port Crescent State Park
• National Weather Service: Great Lakes Safety
• Michigan Sea Grant: Dangerous Currents
• Amtrak