The last recorded fish kill at Rock Creek Lake was in May 2000 and due to natural causes like disease, parasites or stress, according the DNR’s fish kill database.

A swimming advisory has been posted at Rock Creek Lake through Wednesday, July 30, according to the Iowa DNR.

Rock Creek Lake, a 600-acre recreational lake offering swimming, boating and fishing, is four miles north and 10 miles east of Newton.

The north entrance to the state recreation area, sections of Rock Creek Lake Road to the hatchery and portions of roads within the park are impassable.

The Iowa Department of Natural Resources announced Tuesday it was investigating a fish kill at Rock Creek Lake and advised swimmers to avoid the lake until Thursday. According to the DNR, field ...