The beach at the foot of Mount Baldy at Indiana Dunes National Lakeshore will reopen to the public in coming weeks, but the dune where a 6-year-old boy was buried almost four years ago will remain closed except for ranger-led hikes.

Nathan Woessner, of Sterling, Ill., fell into an 11-foot hole, and with more holes expected to occur in that area, more information is needed before the dune can reopen, said Bruce Rowe, supervisory ranger and public information officer for the Indiana Dunes National Lakeshore. That portion of Mount Baldy is over an old oak forest.

Park officials don't have a date for reopening the beach and are awaiting an archaeological study in the area where a sand ramp will be constructed to go from an existing trail to the beach, Rowe said.

The wooden steps that once were there eroded away after a bad storm in October 2014, and park officials don't want to have the same problem with another wooden structure, he said.

Officials also are awaiting a survey of bats in the trees in that area.

"[Reopening] won't be by Memorial Day weekend," Rowe said, though the beach should open in one to two months.

The dune has been closed, except for ranger-led hikes that started two years ago, since the incident involving Nathan, who has fully recovered. Scientists have been working to determine what caused that hole and others found in the same vicinity.

The second of two research studies on the holes has provided a blueprint of the holes. It can guide where it's safe to be on the dune and can be updated for the national lakeshore as the dune shifts over time, said Todd Thompson, director and state geologist with the Indiana Geological Survey in Bloomington.

"Our job was to come up with a map that actually could be a problem zone," he said.

Erin Argyilan, an associate geology professor at Indiana University Northwest in Gary, had an early theory that old, rotting trees buried beneath the shifting dune were causing the holes.

Thompson, who's worked with Argyilan, built on that theory in his research. In August 2014, he and other researchers used two approaches to determine what was under the dune – ground-penetrating radar and a coring device to collect sediment samples.

"That was our job, to try to figure out what it looked like inside the dune," Thompson said.

Researchers found an older dune under Mount Baldy that was covered with trees and soil. The spot where the two dunes were within about 16 feet of each other is where Nathan fell into the hole.

"We now have an area on the dune that could be a potential problem," Thompson said, noting that an aerial 1935 photo of Mount Baldy was used to mark where trees were located before they were covered with sand.

The study took about two years, he said, and a report on the study was submitted to park officials in September. Park officials will generate their own report on the study.

"We know what that landscape looks like, which we didn't know before," Thompson said, adding that the ranger-led tours are based on the map.

A version of this article appeared in print on May 07, 2017, in the News section of the Chicago Tribune with the headline "Dunes beach to reopen 4 years after boy trapped" —
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