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State Park · OH

Grand Lake St. Marys State Park

Grand Lake St. Marys State Park, centered around one of Ohio’s largest inland lakes, offers diverse outdoor recreation including boating, fishing, hiking, and camping in a scenic combination of water and woodland habitats.

State Park5,2504+ Trails

Designation

State Park

Total Wilderness Area

5,250

Elevation / Terrain

Diverse Wilderness

Field Editorial Guide

About Grand Lake St. Marys State Park

Grand Lake St. Marys State Park, centered around one of Ohio’s largest inland lakes, offers diverse outdoor recreation including boating, fishing, hiking, and camping in a scenic combination of water and woodland habitats.

Wilderness Landscape & Natural Heritage

Grand Lake St. Marys State Park is located in western Ohio and envelops Grand Lake St. Marys, a 13,500-acre artificial reservoir originally constructed in the 19th century as a feeder for the Miami and Erie Canal. The park covers over 5,000 acres, featuring extensive shoreline, wetlands, and wooded areas. It provides vital habitat for waterfowl, fish species, and other wildlife amidst its mixed oak, maple, and sycamore forests. Visitors come to enjoy fishing for bass, bluegill, and catfish, as well as boating, kayaking, and paddleboarding on the lake's calm waters. The park includes more than 30 miles of trails serving hikers, mountain bikers, and equestrians. Its campgrounds offer both modern amenities and rustic settings, making it a favored destination for families and outdoor enthusiasts alike. Historically, the reservoir was engineered in the 1820s and remains a prominent landmark reflecting Ohio’s canal era. During warmer months, the park hosts popular events such as birdwatching tours and fishing tournaments. The mix of aquatic and terrestrial environments provides varied wildlife viewing opportunities, especially during migratory seasons. Overall, Grand Lake St. Marys State Park presents a well-rounded outdoor experience that combines water-based fun with woodland exploration, ideal for visitors seeking both active recreation and tranquil natural settings.

Field Guide · State Park
Adventure Destinations

Notable Destinations Near Grand Lake St. Marys State Park

Scenic viewpoints, outdoor landmarks, and notable points of interest within 30 miles.

Key Wilderness Highlights

✦ Grand Lake St. Marys Reservoir – one of Ohio’s largest man-made lakes perfect for boating and fishing✦ Extensive trail system with over 30 miles for hiking, biking, and equestrian use✦ Robinson Bay – a popular spot for waterfowl viewing and water activities✦ Historic canal remnants and interpretive markers detailing the area’s 19th-century engineering heritage
Wilderness Recreation

Outdoor Adventures in Grand Lake St. Marys State Park

Explore curated guides for top outdoor sports, trail networks, and wilderness activities.

Park Recreation

Hiking

Available in Grand Lake St. Marys State Park
Park Recreation

Camping

Available in Grand Lake St. Marys State Park
Park Recreation

Wildlife Viewing

Available in Grand Lake St. Marys State Park
Park Recreation

Mountain Biking

Available in Grand Lake St. Marys State Park
Park Recreation

Fishing

Available in Grand Lake St. Marys State Park
Park Recreation

Paddle Sports

Available in Grand Lake St. Marys State Park
Park Recreation

Snow Sports

Available in Grand Lake St. Marys State Park
Park Recreation

Climbing

Available in Grand Lake St. Marys State Park
Park Recreation

Scenic Drives

Available in Grand Lake St. Marys State Park
Park Recreation

Photography

Available in Grand Lake St. Marys State Park
The Ranger Station

Visitor Logistics & Essential Planning

Everything you need to know about entrance passes, seasons, visitor centers, road transit, and wildlife safety in Grand Lake St. Marys State Park.

Passes & Fees

Entrance Requirements & Interagency Passes

Entrance to the park requires a state park vehicle permit or daily entrance fee; boat launch fees may apply.

Wilderness Checklist

Carry paper topographic map & compass in remote zones.
Store all food and scented items in approved bear canisters.
Check wildfire / smoke advisories before backcountry departure.
Pack out everything you pack in (Leave No Trace).
Wilderness Stays

Camping & Overnight Stays in Grand Lake St. Marys State Park

Frontcountry developed campgrounds, backcountry wilderness permit guidelines, and starry-night camping advice.

Grand Lake St. Marys Campground

Offers over 200 campsites including electric hookups, restrooms, showers, and easy lake access.

Robinson Bay Primitive Campground

Rustic camping closer to Robinson Bay, ideal for those seeking a quiet, natural setting near water.

Adventure Basecamps

Gateway Towns Near Grand Lake St. Marys State Park

Stay, dine, and gear up in these mountain towns and scenic basecamps surrounding the park.

Celina
⌖ 0.96 miles
Gateway Basecamp

Celina, Ohio

A friendly small town on the shores of Grand Lake St. Marys offering diverse outdoor activities including paddling, fishing, biking, and seasonal recreation.

Late Spring through Early FallExplore Town
St. Marys
⌖ 9.37 miles
Gateway Basecamp

St. Marys, Ohio

A peaceful small town offering access to flatwater paddling, cycling routes, and nearby nature reserves with a calm and friendly Midwestern outdoor feel.

Spring through FallExplore Town
New Bremen
⌖ 11.86 miles
Gateway Basecamp

New Bremen, Ohio

A quiet, historic town with easy access to scenic rural landscapes for low-key outdoor recreation and local trail exploration.

Spring through FallExplore Town
Spencerville
⌖ 16.19 miles
Gateway Basecamp

Spencerville, Ohio

A quiet rural town offering access to gentle outdoor activities with a focus on paddling, cycling, and exploring nearby state parks and waterways.

Spring through FallExplore Town
Wapakoneta
⌖ 19.50 miles
Gateway Basecamp

Wapakoneta, Ohio

A friendly Midwestern town offering gentle outdoor experiences focused on water sports, hiking, and cycling with easy access to rivers and nature preserves.

Spring through FallExplore Town
Ansonia
⌖ 22.53 miles
Gateway Basecamp

Ansonia, Ohio

A small, quiet town offering easy access to peaceful outdoor activities with nearby rivers and trails ideal for paddling and nature exploration.

Spring through FallExplore Town