Editor’s note: a slight change of pace from Morgan, our resident geology buff, as this look into Indiana Dunes National Park focuses more on the ecology. For more of Morgan’s writing, click here to visit her index page.

One of the more recent additions to the US National Parks system is Indiana Dunes National Park (added in 2019). Having grown up nearby (close to Chicago’s O’Hare Airport) I admittedly found it difficult to picture plain beige after-prom-destination Indiana Dunes being elevated to the same level as Yosemite, Grand Teton, or Lassen National Parks. However, an easy hour road trip to the park left me far more educated about (and surprised by) the ecological gem that’d been right under my nose for such a large portion of my life.

While most US National Parks addicts might visit the 64 sites seeking challenging hikes or mountain views, some National Parks are actually created for other reasons instead. Indiana Dunes was chosen because of its unique ecological and geological value – but don’t worry; it contains some 50 miles of trail, too.

A ranger-led guided walk, available at the Dunes as it is in many national parks, taught us quite a bit about the area. The rangers pointed out unique mushrooms, wonderfully fragrant sarsaparilla plants, and several markers (fence posts, street depressions, and so on) of the neighborhood that used to occupy the area before nature reclaimed it. Additionally, one of the bogs within the park is accessible only on a ranger-led trip, so I recommend you take advantage of the opportunities available.

Indiana Dunes Ecology

One of the reasons the Dunes are so special is that the area contains a unique overlap of several diverse ecosystems, including one that’s becoming exceedingly rare. Black Oak Savannas form when prairies border hardwood forests. They typically contain a mix of scattered oaks within prairie grasses, reflecting their location between forests and prairie areas, with very little medium-height shrubbery between those two levels of vegetation. These savannas thrive best with regular controlled fires, which help keep the tree canopies sparse enough for the black oaks to thrive. Over time, fire prevention efforts as well as land development have decreased the amount of Black Oak Savanna at an alarming rate.

Indiana Dunes National Park contains one of the best remaining examples of Black Oak Savanna in the US, since at this time less than 0.02% of high-quality Black Oak Savanna remains in the Midwest. Elevating the status of this area to National Park allows for greater conservation and restoration efforts for these black oak habitats, which are home to quite a few other endangered organisms. Other habitats in the park that are protected by National Park status include several bog and wetland areas.

The unique combination of ecosystems has provided a rich atmosphere for all kinds of life. During a hike you might encounter the endangered Karner blue butterfly, which is dependent on the wild lupine that dots the dunes. Hundreds of bird species including blue heron call the park home, since the area serves as a common location for migrating birds to rest. Their migratory patterns as well as the complexity of the overlapping ecosystems have brought over 1,100 unique flowering plants and ferns to the park, earning it fourth for biological diversity out of all the US national parks.

The Landscape of Indiana Dunes National Park

The park may be named after the sandy beachside dunes, but the constantly shifting ridges that make up a part of Lake Michigan’s shore aren’t the only environment contained in the park’s 15,000 acres. In addition to the Black Oak Savannas and the dunes themselves, you’ll find forests, prairies, swamps, bogs, fens, and more.

One of the significant features of the area that contributed to its preservation status is the visibility of the geologic records: the park’s landscapes clearly define at least four iterations of Lake Michigan’s formation over billions of years. The park’s clear history of the creation process of Lake Michigan makes it a unique place to study geological evolution of a large freshwater lake.

That process went as follows: Lake Michigan and the other Great Lakes were created by a combination of plate tectonics and glaciers, beginning 1.2 billion years ago when two plates pulled apart in a process known as the Midcontinent Rift. The depression left between those separating plates sometimes coursed with moving lava, then was later covered in ice and carved into shape as thick glaciers migrated back and forth over the same area multiple times. The Great Lakes then formed about 10,000 years ago. The first dunes in the area at that time, created by glacial erosion and weathering of rocks, are still visible and now host one of the aforementioned ecosystems: the established forests. The more recent, visibly sandy dunes of today formed roughly 5,900 years ago. Portions of the park are what’s known as a moraine: hills or ridges made by piles of debris that were carried and pushed by the glacial movement.

The Indiana Dunes, like most dunes, constantly shift and change with wind and other weather patterns. Mount Baldy, which is the most active of the dunes at the park, can shift an alarming 18 feet each year depending on weather! This is an extremely fast movement considering normal geologic timescales.

Nearby

While I could talk at length about the attractions of sweet home Chicago, just an hour away, the Indiana Dunes area itself also has a bustling beach scene during warmer months, as well as camping and trails throughout park-adjacent areas. Additionally, the Indiana Visitors Center near the Illinois border has its own lovely charm. When we stopped for a quick break, the massive exhibit honoring A Christmas Story, based on the town of Hammond, Indiana, called for at least an hour of joyful exploration.

While it may seem like a skippable National Park when compared with the massive trees in Redwoods National Park or the austere views of the Grand Canyon, Indiana Dunes National Park is definitely worth a visit – then, head to Chicago for a sports game, a hot dog, and a deep-dish pizza, naturally.

Like it? Pin it!