Au Gres is located in eastern Arenac County a few miles from the Lake Huron shoreline. French explorers referred to the area as having "gritty stone," hence the name Au Gres. Saginaw Bay on Lake Huron contains one of the largest coastal wetland systems in the United States. A public boat launch operated by the Michigan DNR provides access to the bay and walleye and perch fishing opportunities. Water quality monitored as needed.