The islands have almost disappeared because of erosion from waves. The U.S. Army Corps of Engineers is working to rebuild them by constructing more than four miles of wave barriers and filling in the area around the islands with material from dredging over the next 30 years, Press-Gazette Media reported Monday.
The process is eventually expected to create 270 acres of wildlife habitat.
"This year, the only thing left is repairing Lineville Road, and then the dredging will be deposited there every other year for the next 30 years," said Dean Haen, Brown County port director.
Green Bay, Milwaukee and Duluth-Superior are among the harbors being dredged.
The Army Corps also is finishing work on Renard Island, which was built with contaminated dredge materials. The Corps is capping it with clean soil before turning it over to Brown County, which wants to use it as a park.