Cowles Bog is named for the scientist Henry Chandler Cowles from the University of Chicago. Cowles is one of the founders of the modern science of ecology, and a tireless champion of the dunes in the early twentieth century. Today Cowles Bog is home to over 400 species of plants, and countless varieties of mushroom and fungi. The National Audubon Society designated Cowles Bog an Important Bird Area, and the woods and wetlands here attract a stunning array of birds and waterfowl. 

In 1953 Indiana Dunes champion Dorothy Buell and the newly formed Save the Dunes Council purchased the land in hopes it would one day serve as the foundation for a park. In many ways Cowles Bog is the heart of the Indiana Dunes.

An aerial view of Cowles Bog

The Geological Story of Cowles Bog

Like the rest of the Indiana Dunes, Cowles Bog’s story traces back to the last ice age, when advancing and retreating glaciers carved the landscape and left behind the massive sand dunes and wetlands. In spite of its names, Cowles Bog is scientifically a fen. Bogs, like nearby Pinhook Bog in the Indiana Dunes, are wetlands nourished only by rain or snowfall, resulting in stagnant water that is highly acidic. A fen, on the other hand, is more basic (with a higher pH level) and is fed by fresh groundwater. The combination of the fen, surrounding marsh, and trees makes Cowles Bog what is known as a “swamp complex,” and a vital wildlife habitat.

Aerial view of a water with green and brown vegetation. Trees line the background an a blue sky is above.

Hike the Cowles Bog Trail

Cowles Bog Trail is an Indiana Dunes National Park classic. The trail highlights the park's outstanding plant diversity, yet it is close to some of Northwest Indiana's industry. Explore several distinct habitats along this 4.7-mile trail, including ponds…

The Indiana Dunes is one of the most biodiverse national parks in the entire country. Over 1,100 flowering plant species and ferns make their homes here. How many flowers can YOU find?

Birds You May See

Grab a copy of this self-led birding tour, and visit six of the Indiana Dunes area birding recommended by local birders. Spectacular birds are waiting for you. Can you spot 'em all?

Celebrate the birthplace of plant ecology with your very own t-shirt, pajamas, teddy bear, and more. Shop Cowles Bog products in the Indiana Dunes Passport Collection.

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Birders at Cowles Bog

Noteworthy

A short distance from the trailhead, Cowles Bog trail features a lovely raised boardwalk that allows visitors to walk above this incredible wetland.

In the spring, watch for pairs of Sandhill Cranes raising their newborns in the marsh just off Mineral Springs Road to the east and west.

The northern edge of the trail from the Main Lot takes you by beaver lodges that are right off the trail in the wetland to the south. Watch for them about a mile from the Main Lot.

A beaver den at Cowles Bog
A sandhill crane looks back at something in the distance. It stands in a marshy area with vegetation.

Get Involved

Be the Change — Volunteer! Get more involved with the Indiana Dunes! There are many no-hassle, drop-in volunteer opportunities available for everyone. Just show up!

Be Responsible

Visitors must stay on designated trails at all times. We have created a video to help you learn about your role in enjoying the dunes area safely while minimizing your impact on the park.

Love & Protect the Dunes

Each of us who visit the Indiana Dunes can also help protect natural heritage, biodiversity, and local culture by taking a few simple steps.

Plan Your Visit

  • 1450 N. Mineral Springs Rd.
  • 219-395-1882

This is where Henry Chandler Cowles conducted his landmark study of the dunes’ vegetation succession. You can embark on the 4.5 miles of interconnected trails, choosing a short, moderate hike…

What to Expect

There are two parking lots available at Cowles Bog. For quick access to spring flowers, and ponds filled with Great Blue Herons, Canada Geese, and Capsian Terns, take a left after the railroad tracks on Mineral Springs Road and park in the paved Greenbelt Trailhead lot.

For the fastest route to the boardwalk viewing platform, enter the trailhead through the main parking lot which is located just before the Ogden Dunes town guardhouse.

The trail is a mixture of loose sand and packed dirt with moderate to rugged dune climbs. Visitors will hike along ponds, marshes, and black oak savannas, eventually leading to Lake Michigan.

An aerial view of Cowles Bog

Main Lot (north): 1450 North Mineral Springs Road, Dune Acres, IN 46304

Look for the gravel entrance road on the right just before the town guardhouse.

  • Free to enter
  • Open daily from 6:00 am to 11:00 pm
  • 4.7 miles with loops for shorter routes
  • Not wheelchair accessible
  • No handicap parking
  • No drinking fountains
  • Porta-John available year round

An aerial view of Cowles Bog

Greenbelt Lot (south): 1184 North Mineral Springs Road, Dune Acres, IN 46304

Look for the entrance road on the left just after the railroad tracks.

  • Free to enter
  • Open daily from 6:00 am to 11:00 pm
  • 4.7 miles with loops for shorter routes
  • Not wheelchair accessible
  • No handicap parking
  • No drinking fountains
  • Porta-John available year round