Originally constructed as a feeder reservoir for the Miami-Erie Canal, Grand Lake St. Marys was for many years recognized as the largest man-made reservoir in the world. The 13,500-acre lake is the gateway to swimming, boating, camping and fishing in one of Ohio's oldest state parks.
Camping
34 full hookup sites
158 electric sites
10 non-electric sites
Facilities include flush toilets, laundry, showers and a dump station.
Pets are permitted except for the area in and around the Getaway Rentals.
Separate shelter house, oversize game board, splash pad, swimming beach, boat launch and boat docks/tie-ups are available to registered campers.
Seasonal naturalist programs are offered on weekends Memorial Day through Labor Day.
Full-service camp store loans games, fishing and sporting equipment to registered campers
Bike rentals and miniature golf course
Activities
Boating
The 13,500-acre lake allows unlimited horsepower. A 300-foot no-wake zone has been established and is enforced around the lake’s 52 miles of shoreline.
Eight state-operated launch ramps provide access to the lake. Several private launch ramps also exist along the shallow shoreline.
Seasonal dock rentals are available, call the park office for information.
Dog Park
Two dog parks are available. One the East Bank is the Fur-Ever Friends Dog Park. On the West Bank is the Celina Rotary Dog Park. Both offer a place for your dog to frolic without a leash.
Fishing
Largemouth bass, white and black crappies, bluegills, walleye, channel and flathead catfish, yellow perch, bullheads, carp, and ******* are found in the lake. Gizzard shad is the primary forage species for predators. A valid Ohio fishing license is required. An ADA Accessible Fishing Pier is available at East Bank and an ADA accessible fishing access area at West Bank.
Hunting
Limited hunting is permitted in designated areas, hunting maps are available in the park office. Seventy seasonal duck blinds are available by a lottery administered by ODNR Division of Wildlife. A valid Ohio hunting license is required.
Picnicking
Several picnic areas with tables and grills are located in scenic areas around the lake on a first-come, first-served basis. Some are covered.
Two first-come, first-served shelter houses are located on the East Bank.
Four reservable shelter houses are located at the west end of the lake
Swimming
Four public swimming beaches are available. Other swimming areas are also provided for boaters. Swimming is permitted during daylight hours only. Visitors swim at their own risk. Pets are not permitted on swimming beaches. Children are also encouraged to enjoy the splash pad at the campground at Grand Lake St. Marys.
Trails
Three trails are within the park. Visitors may also hike down to the canal feeder junction to connect to the Miami Erie Trail, Buckeye Trail and North Country Scenic Trail near the historic Miami and Erie Canal.
West Bank Multi Use Trail - 1.2 miles
East Bank Multi Use Trail - 1.4 miles
Red Wing Trail - 0.65 mile (campground)
Winter Recreation
Under the proper conditions, park visitors can enjoy snowmobiling, ice fishing, and cross-country skiing.
More to Do
Dog parks are located on the west and east banks of the lake.
Miniature golf course
Basketball and volleyball courts
Horseshoe pits
Playground equipment
Nature center offers programs during the summer
Bicycle rental is available
