Hundreds of pounds of garbage has washed onto Lake Michigan shores in recent days, leading to an investigation by the Coast Guard and the temporary closing of a public beach. Trash was strewn along a 10-mile stretch in Mason and Manistee Counties in the northwestern Lower Peninsula. Piles up to eight inches high were reported at a beach in the city of Manistee. Garbage also washed onto private beaches in Holland, more than 100 miles south of Manistee. The trash in Mason and Manistee Counties included medical waste like prescription drug bottles and hypodermic syringes, the authorities said.