The Coast Guard is establishing a temporary safety zone for navigable waters on the Upper Mississippi River between 636-635, east of Island number one hundred seventy-two. The safety zone is needed to protect personnel, vessels, and the marine environment from potential hazards created by high-speed power vessels. Entry of vessels or persons into this zone is prohibited unless specifically authorized by the Captain of the Port, Sector Upper Mississippi River.
Source: Federal Register USCG
Link: Safety Zone; Upper Mississippi River, Prairie du Chien, WI