The Coast Guard is establishing a temporary safety zone for the Mississippi River from mile marker (MM) 219.5 to 218.5 near Grafton, IL. The safety zone is needed to protect personnel, vessels, and the marine environment from potential hazards created by a Missouri National Guard training event near Grafton, IL. 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 Mile Markers 219.5 to 218.5 Grafton, IL