MICHIGAN CITY | Officials at Indiana Dunes National Lakeshore announced Thursday that scientists still do not know what caused holes to appear in Mount Baldy last summer, and the popular attraction will remain closed for further study.
Nathan Woessner, 6, of Sterling, Ill., was swallowed by a hole July 12 and rescued by firefighters.
Two additional holes have appeared since July, park officials said Thursday.
Ground penetrating radar studies performed by the Environmental Protection Agency have identified a large number of anomalies below the dune’s surface, but scientists from the National Park Service, Indiana University and the Indiana Geological Survey still do not know how these holes were formed.
“Mount Baldy is one of the most visited sites in the national lakeshore, attracting thousands of visitors each year” said Acting Superintendent Garry Traynham in a press release. “But the continued development of these holes in the dune surface poses a serious risk to the public. Our first obligation must be to the welfare of our visitors who are here for an enjoyable outing.”
The two additional holes and a number of depressions have been found since July. Officials said the holes are short-lived, remaining open for less than 24 hours before collapsing and filling in naturally with surrounding sand.
Officials at the national lakeshore on Thursday announced more testing will be conducted this summer. That work will include mapping of openings and depressions, as well as scientific studies of the internal architecture of the dune.
Park workers will continue planting marram grass on portions of Mount Baldy where the native dune grass used to grow. The extensive root system of the grass holds sand in place and may also help prevent holes from opening up on the dune’s surface, officials said.
All other beach access areas within the national lakeshore remain open.