Indiana Dunes National Lakeshore was established by Congress in 1966. By that time, humans had already made a great many changes to the lakeshore's natural areas. Many of the white pines were logged in the 1830s and 40s. Farmers started moving into the region in the late 1800s. Industry has existed in Gary and East Chicago, just west of the lakeshore, since around 1900. By the 1930s, residential communities began springing up and this development escalated in the 1950s with the post-war economic boom. The late 1950s and early 1960s brought the development of a coal fired power plant and a steel mill into the midst of extensive natural sand dunes and wetlands. With each of these changes came impacts to the environment.
Logging changed the species composition of the forest and caused erosion in the dunes. The farming movement resulted in the drainage of wetlands, the introduction of exotic species, and the extirpation of predatory animals. Subsequent residential development accelerated the ditching and drainage of wetlands, the modification of land use, and the addition of large numbers of structures. Industrial expansion resulted in increases of many of the previously mentioned impacts as well as increases in air pollution. As development increased, so did efforts to suppress naturally occurring fires. All of these impacts affect the way Indiana Dunes National Lakeshore is managed today. Resource managers are mitigating the damage done in the past.
The national lakeshore features several swimming beaches along the shore of Lake Michigan. These beaches are sometimes impacted by high levels of bacteria after heavy rainfalls and high bacteria levels can be a threat to human health. The national lakeshore monitors the water quality at its beaches on a regular basis during the swimming season, posting warning signs noting high bacteria counts on affected beaches.
The national lakeshore is in the process of restoring portions of an extensive wetland complex called the Great Marsh south of the primary dunes in the eastern half of the park. By plugging ditches, restoring the area's hydrology, removing invasive plants, and planting native species, the lakeshore is re-creating a diverse and beautiful ecosystem. Because wetlands naturally filter contaminated water, restoring the Great Marsh will also help to improve the area's water quality.
In presettlement days, naturally occurring fires cleared the dead wood and maintained prairie and savanna habitats. During the years when fire suppression was the rule, a great many of these open habitats were lost or significantly altered. Not only did this reduce habitat diversity, but it reduced the plant and animal diversity as well. Today, the national lakeshore has a rigorous prescribed burn program which is restoring the area's prairies and savannas and helping to maintain critical habitat for the endangered Karner blue butterfly.
When Indiana Dunes National Lakeshore was established in 1966, close to 1,000 commercial buildings and home sites were included in the park's boundary. A number of historic structures have been preserved, and some other buildings were renovated to create office space, interpretive centers, and other park facilities. The majority of these building are being removed in order to restore the natural areas that once were there. Resource managers take great pains to collect seeds from a variety of native plants within the park to ensure that these areas are planted with native species of local genotype.
Invasive exotic plants brought here either intentionally or accidentally from other parts of the world, outcompete our native plants for life-giving resources. The lakeshore is working hard to reduce the population of these undesirable species with a goal of eventually eliminating them. Intensive programs to remove purple loosestrife, garlic mustard, and an invasive hybrid cattail are presently under way.
A natural pattern of erosion and deposition moves sand in a westward direction along our area beaches. In several cases breakwaters and other structures have been built long the Lake Michigan shoreline. These structures have interrupted the natural movement of sand, allowing erosion to continue while simultaneously impeding deposition. The net result has been increased erosion of the lakeshore's beaches and dunes. To protect its shoreline, the lakeshore responded with a beach nourishment project to replenish the sand that was no longer being deposited naturally.
Other factors adversely impacting the lakeshore's resources are also being addressed, and Indiana Dunes National Lakeshore will continue to take a proactive management approach.