Personal data of those registered with the Three Rivers Park District's reservation database has been compromised. 

"Three Rivers Park District recently discovered that unknown persons attempted to access customers’ personal data," Three Rivers Park District said in a statement Friday afternoon.

It's unclear exactly how many usernames and passwords were accessed, but the park district stresses credit card numbers and other identifying information was not accessed or downloaded. 

"That data is stored on an external system by a national credit card provider whose system is secure," Three Rivers Park District Superintendent Cris Gears said in an email to patrons Friday.

The Park District has reviewed and bolstered its firewalls, and technical staff and outside consultants "have made assurances that the system is safe to use," according to the statement. "Staff will continue to take all appropriate steps to ensure that park users’ personal information remains safe and secure."

It wasn't immediately clear if the incident is being investigated by law enforcement. All households in the park district's database have been alerted to the situation. 

Users accessing the Three Rivers Park District's online reservation system will be prompted to change their passwords the next time they log in to the system, according to Gears, and the online reservation system will once again be available beginning on Monday, April 30.

"On behalf of the Board of Commissioners and all of my colleagues at Three Rivers Park District, I sincerely apologize for this inconvenience," Gears said.

The Three Rivers Park District operates dozens of campgrounds, trails and parks in seven metro area counties, including the Elm Creek Regional Park, Fish Lake Regional Park and Eagle Lake Regional Park in Maple Grove.

Patch will have updates on this story as it becomes available.