Every Boat Ramp on Grand Lake St. Marys

About Grand Lake St. Marys

Grand Lake St. Marys is the largest inland lake in Ohio at 12,600 acres, located in Mercer and Auglaize counties in the western part of the state. Built in the 1840s as a canal feeder reservoir, this historically significant lake is remarkably shallow with a maximum depth of just 7 feet. Despite water quality challenges in recent years, the lake continues to support productive crappie and channel catfish populations.

Crappie fishing is the primary draw, with the vast shallow flats and abundant brush piles holding large schools of fish. Channel catfish grow to impressive sizes in the fertile water, and bluegill and yellow perch provide steady panfish action. Largemouth bass are present along the shoreline vegetation and around docks and piers. The lake's immense size means there is always room to find productive water away from crowds.

The towns of Celina and St. Marys anchor opposite ends of the lake and offer full services including marinas, bait shops, restaurants, and lodging. Grand Lake State Park provides launch ramps and camping facilities. The annual Governor's Cup Regatta and other events make the lake a hub for the western Ohio lake community.

Nearest towns: St. Marys, Celina, Montezuma