NPS Image Collection
Indiana Dunes National Lakeshore was established by Congress in 1966. By that time, people had already made many changes to the national lakeshore's natural areas. Many white pines were logged in the 1830s and 40s. Farmers started moving into the region in the late 1800s. Around 1900 industry came into Gary and East Chicago, just west of the national lakeshore. By the 1930s, residential communities sprang up and 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 some 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 similar impacts as well as an increase in air pollution. As development increased, so did efforts to suppress naturally occurring fires. All of these impacts affect the way the national lakeshore is managed today. Resource managers are mitigating the damage done in the past.
Water Quality Monitoring
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. 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.
NPS image collection
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 national 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 dead wood and maintained prairie and savanna habitats. During the years when fire suppression was the rule, many woody trees and shrubs encroached on these open habitats and prairies and savannas 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 controlled burn program which is restoring the area's prairies and savannas and helping to maintain critical habitat for the endangered Karner blue butterfly.
Home Site Restoration
When the national lakeshore was established in 1966, close to 1,000 commercial buildings and home sites were included within 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 collect seeds from a variety of native plants within the park to ensure that these areas are planted with native species of local genotype.
NPS image collection
Invasive exotic plants, brought here either intentionally or accidentally from other parts of the world, out-compete native plants for life-giving resources. The national lakeshore is working 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 underway.
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 national lakeshore's beaches and dunes. To protect its shoreline, the national lakeshore responded with a beach nourishment project to replenish the sand that was no longer being deposited naturally.
The national lakeshore is taking a proactive management approach to addressing other factors that are adversely impacting its resources.
Did You Know?
Cowles Bog is not a true bog but rather a fen because it has an underground water source. This water source has contact with limestone bedrock, making the fen’s water slightly alkaline. Indiana Dunes National Lakeshore is restoring a portion of this fen.