Grand Lake St Mary's

Mercer County, Ohio

13,356.1

Acres

140.3 mi

Shoreline

Fish Species

Local Guides

Depth Maps & Lake Info

Showing 9 nearby bait & tackle shops on the map.

Grand Lake St Marys State Park, OH

Weather forecast for Grand Lake St Mary's — check wind, rain, and temperature before you go
GPS: 40.5178°N, 84.5002°W — Get Directions
View on Ohio DNR Map Viewer for the latest survey data and lake info
Review Ohio fishing regulations for season dates and limits
An Ohio fishing license is required for ages 16+ — buy online at ohiodnr.gov

Data sourced from Ohio DNR Division of Wildlife. Last verified: March 19, 2026. Learn how we maintain this data.