Chesterton Tribune



NPS says Mt Baldy to remain closed as research on holes in dune continues

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For the purpose of public safety, the National Park Service announced on Thursday that Mount Baldy, its parking lot, trail, and beach in front of the dune will remain closed to all vehicular and pedestrian access as scientists investigate what’s causing holes to form inside the dune.

The NPS said in a press release that despite the use of ground penetrating radar, and data gathering at two additional holes that were located since last July, scientists still don’t know why they have appeared at Mt. Baldy in Indiana Dunes National Lakeshore.

“Mount. Baldy is one of the most visited sites in the national lakeshore, attracting thousands of visitors each year” said Acting Superintendent Garry Traynham. “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.”

Ground penetrating radar studies by the Environmental Protection Agency (EPA), have identified a large number of anomalies below the dune’s surface, at least 66, but analysis by scientists from the National Park Service, Indiana University and the Indiana Geological Survey have not yielded answers on how these holes form. One such hole, up to 11 feet deep, nearly cost a 6-year old Illinois boy his life last summer at the National Lakeshore’s most popular sand dune.

Mt. Baldy has been closed since the incident occured on June 12, 2013.

The two additional holes and a number of depressions have been found during the ongoing investigation and continued monitoring of the dune. Scientists report that the holes are short-lived, remaining open for less than 24 hours before collapsing and filling in naturally with surrounding sand.

NPS Spokesperson Bruce Rowe had told the Chesterton Tribune earlier this month that there are a lot of objects under the sand that could be causing the anomalies such as old pop cans or a fence line but they are unidentifiable at this point.

Scientists are now preparing for a more comprehensive investigation of the dune this summer. This study will include mapping of openings, depressions, and anomalous features, the use of multispectral Ground-Penetrating Radar (GPR) and coring to develop a better understanding of the overall internal architecture of the dune, and detailed GPR and coring of some of the anomalies identified in the EPA report.

During the research work, the park’s resource managers will continue planting marram grass on portions of Mt. 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.

All other beach access areas within the National Lakeshore are currently open and visitors are asked to stay on the established trails to prevent erosion and resource damage.

For information, and to view the EPA’s Geophysical Survey Report, a Core Study, photos, video, and graphics on the Mount Baldy research, go to



Posted 4/25/2014