The island will be closed until park rangers are confident black bears are staying away from campsites and cabins, the Superior (Wis.) Telegram reported Friday.
Rangers directed guests to other islands in the park area.
Sand Island was closed to overnight visitors Monday, after bears entered campsites and damaged property.
A bear climbed onto a boat twice and removed food from a cooler Wednesday, the newspaper said.
"The late spring means that bears probably can't find much to eat right now on the islands, making human food really tempting," Apostle Islands National Lakeshore Superintendent Bob Krumenaker said.