What You'll Find at Mary Island State Park

Mary Island State Park sits in the Thousand Islands region of the St. Lawrence River near Alexandria Bay, about 90 minutes northeast of Syracuse. The park occupies a small island accessible only by boat, making it a destination for anglers willing to launch from nearby marinas or public boat ramps. The surrounding river holds smallmouth bass, largemouth bass, walleye, and northern pike, with seasonal runs of muskellunge in deeper channels.

The island itself offers primitive camping and day-use access, but most visiting anglers fish the waters immediately around it rather than staying overnight. The shallow bays and rocky structure near the island create habitat that attracts bass year-round and pike in spring and fall. Water clarity varies with season and recent rainfall—summer often brings clearer water, while spring runoff can cloud conditions.

Key Takeaways

  • Mary Island is reachable only by private boat or charter, with the nearest public launch at Grass Point State Park about 3 miles away.
  • Smallmouth bass fishing peaks in May through June and again in September through October, with fish holding on rocky points and drop-offs.
  • A New York State fishing license is required, and the St. Lawrence River is jointly managed by New York and Canada, so check current regulations before fishing.
  • The island has no services—bring your own water, fuel, and supplies if you plan to camp or spend a full day fishing.
  • Boat traffic can be heavy in summer, especially near the shipping channel; early morning and late evening offer calmer conditions and better fishing.

Seasons and What to Expect

Spring (April through May) brings the most active fishing as water temperatures climb from the 40s into the 50s. Smallmouth bass move from deep winter holes into shallower bays to spawn, and pike follow the same pattern. Early morning and dusk are most productive, with topwater lures and soft plastics working well in 6 to 12 feet of water around rocky structure.

Summer (June through August) slows the bite as water temperatures reach the upper 70s. Bass move deeper or into shade during midday, but early morning and evening sessions can still produce. Walleye become more active at night, and some anglers switch to live bait or jigging in deeper channels. Boat traffic peaks during this season, making quieter times harder to find.

Fall (September through October) rivals spring for fishing quality. Cooling water temperatures push bass back into shallower feeding zones, and pike become aggressive as they prepare for winter. Largemouth bass, less common in the river than smallmouth, show up more reliably in fall in the weed-lined bays on the island's south and west sides.

Winter (November through March) is possible but challenging. The river rarely freezes solid enough for safe ice fishing near the island, and boat access becomes weather-dependent. Some anglers target walleye through the ice in protected bays, but conditions change rapidly and require local knowledge.

Access and Boat Launch Information

Mary Island has no road access. The closest public boat launch is at Grass Point State Park, located on the mainland about 3 miles south of the island. The ramp is free and accommodates trailers, with parking for vehicles and boats. From Grass Point, the run to Mary Island takes 10 to 15 minutes depending on water conditions and your boat speed.

Alexandria Bay, about 2 miles west of the island, has several private marinas that offer launch services, fuel, and boat rentals if you do not have your own vessel. Expect to pay a launch fee at private facilities. Charter captains based in Alexandria Bay also offer guided trips to the island and surrounding waters if you prefer not to navigate on your own.

The island itself has a small dock on the north shore suitable for tying up during the day. Overnight mooring is not may provide, so check with the New York State Parks office before planning a multi-day trip. Camping is available on the island but requires advance reservation through the state parks system.

Regulations and Licensing

A New York State fishing license is required for all anglers 16 and older. Licenses are available online through the DEC website, at sporting goods stores, and at some marinas. A one-day license costs less than a full-year license if you are visiting for a short trip.

The St. Lawrence River is jointly managed by New York and Canada, and regulations can differ depending on which side of the international boundary you are fishing. Mary Island is on the New York side, so New York regulations apply. Current rules include a 15-inch minimum length for smallmouth bass and a 24-inch minimum for walleye. Pike and muskie have separate minimums that change periodically, so check the current DEC guide before you fish.

Catch-and-release is encouraged for muskie and pike, though harvest is legal within size limits. Some anglers practice voluntary catch-and-release for all species to preserve the fishery. Bag limits (the number of fish you can keep per day) vary by species and are listed in the DEC's annual fishing guide.

What Gear and Tackle to Bring

Smallmouth bass respond well to soft plastic tubes (3 to 4 inches), crankbaits that mimic baitfish, and topwater plugs in low-light conditions. Jigs tipped with live crawfish or minnows work year-round. A 6 to 7-foot medium-action spinning rod with 8 to 10-pound braided line is standard for most anglers.

Pike fishing calls for heavier tackle—a 7 to 8-foot medium-heavy rod with 15 to 20-pound line and a wire or heavy fluorocarbon leader to prevent bite-offs. Large swimbaits, spinnerbaits, and topwater lures draw strikes. Walleye anglers often use live minnows or small jigs in deeper water, particularly at night.

Bring polarized sunglasses to spot fish in shallow water and to reduce glare off the river. A depth finder helps locate structure and drop-offs, especially if you are unfamiliar with the area. Sun protection, a hat, and a light rain jacket are essential—weather on the river changes quickly, and there is no shelter on the island itself.

Camping and Day-Use Facilities

Mary Island has four primitive campsites available for overnight use. Each site has a fire ring and a picnic table but no running water, electricity, or bathroom facilities. Reservations are required and can be made through the New York State Parks reservation system. Sites fill quickly during peak season (May through September), so book well in advance.

Day-use visitors can land on the island and fish from shore or use the dock area without a reservation. There are no services on the island—no food, water, or fuel. Bring everything you need for the day, including fresh water for drinking and cooking. A portable camp stove is allowed if you camp overnight.

The island is small (about 6 acres), so most anglers fish from boats rather than wading or casting from shore. The rocky shoreline makes wading difficult and potentially dangerous. If you do wade, wear a life jacket and water shoes with good grip.

Nearby Alternatives and Complementary Fishing

If Mary Island is crowded or conditions are poor, several other Thousand Islands locations offer similar fishing. Wellesley Island State Park, also in the region, has a boat launch and day-use area with better facilities than Mary Island. The waters around Wellesley hold the same species and respond to similar techniques.

The St. Lawrence River main channel between Alexandria Bay and the Seaway Trail holds walleye and pike in deeper water. Charter captains often fish these areas when the shallower bays around the islands are too crowded. Muskie fishing is possible in the main channel during summer and fall, though it requires patience and specialized tackle.

Chaumont Bay, about 30 miles west, is a larger freshwater bay that connects to Lake Ontario and offers different habitat—more weed beds and softer bottom than the rocky Thousand Islands. It is a good alternative if you want to explore beyond the immediate area.

Frequently Asked Questions

Do I need a boat to fish Mary Island?

Yes. The island is accessible only by water. If you do not own a boat, you can rent one at Alexandria Bay marinas or hire a charter captain to take you to the island and surrounding fishing spots. Grass Point State Park launch is the closest free public ramp.

What is the best time of year to fish here?

May through June and September through October are peak seasons for smallmouth bass. Spring offers spawning fish in shallow water; fall brings aggressive feeding as water cools. Summer is slower but still productive early and late in the day. Winter is possible but weather-dependent and requires local knowledge.

Can I keep fish I catch at Mary Island?

Yes, within New York State regulations. Smallmouth bass must be at least 15 inches, walleye 24 inches. Bag limits vary by species and are listed in the current DEC fishing guide. Many anglers practice catch-and-release for pike and muskie to preserve the fishery.

Is there drinking water on the island?

No. The island has no services. Bring your own fresh water for drinking and cooking. If you camp overnight, plan for water needs for the full stay. Some anglers bring a water filter and collect river water, but treating it is necessary.

How far is Mary Island from Syracuse?

About 90 minutes by car to Alexandria Bay, the nearest town with marinas and services. From there, the boat ride to Mary Island is 10 to 15 minutes. Plan for travel time and allow extra time to launch and navigate if you are unfamiliar with the river.