Grand Lake St. Marys
United States, Ohio
Grand Lake St. Marys
LocationUnited States, Ohio
RegionOhio
TypeState Park
Coordinates40.5451°, -84.4381°
Established1949
Area0.22
Nearest CitySt. Marys (3 mi)
Major CityDayton (55 mi)
About Grand Lake St. Marys
County: Mercer and Auglaize Counties. Approximately 13,500+ acres (54.63 km²) including one of the largest man-made lakes in the United States