Independence Grove Forest Preserve in Libertyville will remain closed until further notice following a bomb threat that shut down activities Tuesday night, officials said.
One of the Lake County Forest Preserve District's largest and most popular facilities remained closed Wednesday as authorities led by the U.S. Postal Inspection Service, with assistance from the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Lake County Forest Preserve Ranger Police, continued the investigation.
It came a day after officials canceled Tuesday night's Events in the Plaza concert and told all visitors to preserve to leave.
However, what that investigation entailed was not clear, although activities such as camps that had been planned for at Independence Grove were canceled, diverted or rescheduled.
Postal authorities were not available for comment Wednesday.
While authorities said the threat was received by mail and was to a specific target at Independence Grove, further details such as why the preserve may have been singled out were not forthcoming Wednesday.
Ranger Chief John Tannahill said the preserve will remain closed until a complete investigation is completed.
"We have closed the forest preserve until we can secure the facility and make sure it's safe," he said. "The threat is credible enough that we are closing the preserve and investigating."
Ann Maine, president of the forest preserve district board, has been out of town but in contact with authorities. She emphasized the concert, one of a popular series held at the Millennia Plaza amphitheater at 7:30 p.m. every Tuesday, was not the target.
"The safety of the visitors to our preserves is always paramount, and we always err on the side of caution," she said.
Independence Grove is on Route 137 east of Milwaukee Avenue near Libertyville. At 1,151 acres it is the fourth largest in the system and considered the busiest and most popular. The preserve features a 115-acre lake and beach, marina, pavilion, cafe and trails and other amenities.
Hawthorn Woods resident Rick Scardino was heading to Independence Grove with friends to see the reggae/rock band Mr. Myers but was turned away by police at the main entrance.
"Nine of us were on our way there, picnic baskets all packed. We were looking forward to it," Scardino said. "It obviously was a disappointment, but we understand the circumstance. (It's) the old adage, better safe than sorry."
Forest district officials did not have an estimate of how many visitors had to leave but said the process went smoothly.
"We went in there with our rangers and started to talk with everybody and everybody was very cooperative and understood," district Executive Director Ty Kovach said.
Kovach said the district was waiting for further details.
"It's really status quo for us right now. Nothing has changed," he said.
Why target Independence Grove?
"We really don't know at this point," he said.
Forest district rangers are "taking every necessary precaution to secure the site and protect the public until the investigation is complete," Tannahill said Wednesday.
Independence Grove will reopen when authorities deem it safe, he added.
• Daily Herald staff writer Lee Filas contributed to this report.