Open Memorial day weekend to Labor day. Amenities include until further notice, Au Gres shall be a harbor-of-refuge without any amenities or on-site staff. All slips are non-reservable and are free on a first-come, first-serve basis. If mooring at a slip, please report your stay to the Michigan DNR at (989) 686-9619. If no one answers, please leave a voice mail with your name, cell phone number, boat name and registration number, home port, and dates of stay. For those in boats entering from a foreign port or place, the Au Gres State Dock is NOT a Port of Entry into the United States.