Holes in Indiana Dunes’ Mount Baldy likely caused by buried ‘ghost forest’

MICHIGAN CITY, Ind. — Trees slowly buried by windblown sand are likely the root cause of dangerous holes that have appeared in the towering Mount Baldy sand dune in the Indiana Dunes National Lakeshore, a geologist says.

Erin Argyilan believes pockets were formed around tree branches and trunks enveloped by Mount Baldy. She says that created a “ghost forest” beneath the sand.

The popular tourist destination was closed in 2013 after 6-year-old Nathan Woessner, a boy from Sterling, Illinois, who was 6 at the time, was buried in sand for hours before rescuers found him. Miraculously, he survived unharmed. And scientists have been searching for the cause ever since.

Argyilan, who worked with the National Parks Service, will soon have her findings published by an international journal on dunes studies.

Argyilan’s research shows a line of trees standing near the dune in the 1930s was slowly buried, creating unstable areas that could act like a trap door. At one point while studying the dune, an eight-foot hole opened up near Argyilan, though she avoided falling in.

The geologist says 11 holes have been discovered and that she’s certain there are more in the dune, which moves about four feet a year, according to the National Park Service.

“I’d bet any amount of money there are still holes out there,” she said.

The 126-foot-tall dune — about midway between South Bend, Indiana, and Chicago — covers about 100 acres of the 15,000-acre Indian Dunes National Lakeshore.

Park rangers have given guided tours of Mount Baldy since Nathan was was trapped under 11 feet of sand for more than three hours on July 12, 2013. But it has remained closed as a general attraction.