Charity Island, sometimes called Big Charity Island, is the largest island in Saginaw Bay, in the Michigan waters of Lake Huron. The island is 222 acres (0.90 km2) in area and has about 3 miles (5 km) of shoreline. It is part of Whitney Township, in Arenac County. The island was named by lake mariners for its location, placed 'through the charity of God' at the entrance to Saginaw Bay midway between the city of Au Gres, Michigan and "The Thumb". The island also contains an 11-acre (0.04 km²) pond, literally a 'lake within a lake', fed by springs.