Independence Grove Forest Preserve near Libertyville reopened Saturday after officials determined a bomb threat risk had passed and pronounced the area safe for public use.
The beach, marina, picnic areas and trails reopened at 6:30 a.m., and regularly scheduled activities resumed at the Lake County Forest Preserve site on Route 137, which had been closed to the public for more than three days following a credible bomb threat the district received in the form of a letter earlier in the week.
"This is an unusual situation," said Andy Kimmel, the Lake County Forest Preserve District's deputy executive director. "It's the first time in the 20-some years I've worked here that we've had something like this happen."
By 4:30 p.m. Saturday, about 1,300 vehicles had passed through the gates at the preserve, spokeswoman Sue Hawkins said. That's down from almost 3,700 vehicles that visited the preserve last Saturday. Hawkins didn't believe potential visitors were spooked by the threat and stayed away.
"Word didn't get out until this morning that the preserve was open so I don't think many people were aware," Hawkins said. "The people that are there don't seem bothered or timid."
Forest district officials said they will review safety and security measures, and information on the economic impact of closing the preserve will be available within days.
"I can say (the economic impact) was substantial seeing as it was three of the hottest days of the year," said John Tannahill, chief of the Lake County Forest Preserve District Rangers Police.
The threat letter specified the target as a private event scheduled at the preserve and not a district function, and officials notified federal authorities immediately.
Officials closed the preserve Tuesday evening, just before the start of a 7:30 p.m. concert in the Millenia Plaza amphitheater. The concert was canceled and anyone in the preserve at the time was told to leave due to a matter of public safety.
Tannahill described the evacuation as orderly and well-managed with no reports of injuries or damage to property.
An investigation followed. It was headed by the U.S. Postal Investigation Service and consisted of extensive searches by the district's ranger police along with several bomb detection canine teams from the Cook County Sheriff's Police Bomb Unit. They found no suspicious devices or materials anywhere on the property, or in its structures or facilities, district officials have said.
"First and foremost on our minds was to secure the site and protect the public so no harm would come to them from this threat," forest district board President Ann Maine said in a news release Saturday. "We are grateful for the sympathetic support and understanding we have received from our preserve visitors during the closure of Independence Grove, which is one of the most popular outdoor recreation destinations in the county."
Independence Grove is the district's fourth largest forest preserve.
During the investigation, Independence Grove facilities were closed and activities such as camps were canceled, diverted or rescheduled, officials said.
The U.S. Postal Investigation Service is continuing its investigation. Investigators have gathered and sent evidence to their lab for processing and interviewed persons of interest related to the threat, but no arrests have been made, the news release stated.
Maine praised the forest preserve rangers' efforts during the last three days, citing as an example their response to people using the Des Plaines River trail, which remained open. Those people typically stop for water at a facility that was closed during the investigation, she said. To accommodate them, rangers brought ice chests with water bottles, Maine said.
"Part of the training our rangers have is understanding how the preserves are used," she said.
Daily Herald Staff Writer Jake Griffin contributed to this report.