Indiana’s beaches along Lake Michigan have faced dramatic erosion in the last decade, according to the Statehouse File.

The erosion is caused by rising water levels in Lake Michigan, threatening recreational areas around the Indiana Dunes.

With more than 3 million visitors each year, the Indiana Dunes National Park is a major Indiana attraction, ranking just below Yellowstone National Park in terms of tourism. Visitors to these areas generate more than $111 million in revenue each year, the Statehouse File reports.

The Indiana Department of Natural Resources is exploring solutions to the erosion, including adding sand to the affected beaches in a process called nourishment. Between 2011 and 2018, the DNR added thousands of tons of sand in an effort to slow the progress of the erosion.

The Army Corps of Engineers is looking into launching a $1-million investigation spanning two or three years. By the end of that period, the study would identify a cause and solution.

The Dunes are home to valuable plant and animal life, including 1,130 species of plants, 352 species of birds, 46 species of mammals, 23 species of reptiles and 18 species of amphibians.