Garbage also washed onto private beaches Tuesday in Holland, more than 100 miles south of Manistee. It was not immediately clear whether the two were related, Lt. Kristie Cabanting, a Coast Guard spokeswoman in Milwaukee.
A helicopter was undertaking flights to try determining where the garbage came from, she said.
The trash in Mason and Manistee counties included medical waste such as prescription drug bottles and hypodermic syringes, authorities said. But most of the garbage consisted of ordinary household rubbish such as candy wrappers, cigarette packages and plastic food utensils, said Matt Fournier, environmental health sanitarian for the local health department.
Fournier's office analyzes E. coli levels in water samples at area beaches each week. Tests from 22 locations along the coast turned up only one site in Ottawa County with an unusually high reading, but it apparently was unrelated to the garbage, he said.
The Manistee beach was closed while a cleanup crew and workers from the Michigan Department of Environmental Quality hauled away three truckloads.
"With the volume of trash, it had to have come from one common source," Tom Reichard, environmental health director with the local health department, told the Ludington Daily News. Some of the items carried names and addresses from Wisconsin, he said.
The beach reopened Tuesday afternoon, City Manager Mitch Deisch said.
The problem of medical waste in the water made national headlines in 1989 when such items washed ashore on beaches of Lakes Erie and Michigan.