What Mary Island State Park Offers
Mary Island State Park sits in the St. Lawrence River between Alexandria Bay and the Canadian shore, accessible by boat from the mainland. The park is a day-use and camping destination with a small dock, lean-to shelters, and a few cleared campsites on roughly 40 acres. You can fish the river directly from the island or launch a small boat from the mainland to reach deeper water. The island itself draws anglers targeting smallmouth bass, walleye, and northern pike in the channels around it.
The park is managed by New York State Parks and operates seasonally, typically from May through October. There is no vehicle access to the island — you must arrive by private boat, rental boat, or water taxi service. The facilities are basic: no electricity, no running water at campsites, and no restaurant or store on the island itself. Everything you need must come with you or be purchased in Alexandria Bay before you cross.
Key Takeaways
- Mary Island requires a boat to reach; there is no bridge or ferry service, so you must own, rent, or hire a water taxi from Alexandria Bay.
- The park has lean-to shelters and open campsites available for overnight stays during the May-through-October season, with reservations handled through the New York State Parks system.
- Smallmouth bass and walleye are the primary fish species around the island, with the best fishing in the deeper channels and drop-offs on the river's Canadian side.
- All water and supplies must be brought to the island; there are no services, stores, or fuel docks on Mary Island itself.
- Day use is free, but camping requires a reservation and a nightly fee that varies depending on shelter type.
Getting to Mary Island by Boat
If you own a boat, launch from the Alexandria Bay public launch on Church Street (near the waterfront downtown) or from the Grass Point State Park launch a few miles south. The crossing from either launch to Mary Island takes 10 to 15 minutes depending on water conditions. The island dock can accommodate small to medium recreational boats; tie up at the designated mooring field or use the dock itself if space is available.
If you do not own a boat, several rental services operate from Alexandria Bay. Check with the Alexandria Bay Chamber of Commerce or local marinas for current rental rates and availability. A water taxi service also runs from the village waterfront during the season; ask at the visitor center or any marina for the current operator and schedule. The taxi is the most straightforward option if you are traveling light and do not want to manage a rental boat.
Fishing Around Mary Island
Smallmouth bass are the most reliable catch around Mary Island, especially in spring and fall. Fish the rocky shoreline and shallow reefs on the island's perimeter in May and June, then move to deeper channels and drop-offs as water temperatures rise through summer. Walleye fishing peaks in early morning and late evening; they hold near the deeper edges of the channels on the Canadian side of the river. Northern pike are present but less predictable; they prefer the weedier shallows on the American side.
The St. Lawrence River current is strong around the island, so anchor carefully or use a drift approach if you are fishing from a boat. Live shiners and crawfish work well for bass and pike; jigs and live minnows are effective for walleye. If you are fishing from shore or the dock, focus on the deeper water on the north and east sides of the island where the current brings food and fish hold in the channel.
Camping and Overnight Stays
Mary Island has five lean-to shelters and several open campsites available for overnight use. Lean-tos are three-sided structures with a roof and a wooden platform floor; they sleep up to four people and are the most popular option because they provide protection from weather. Open campsites are cleared areas where you can pitch a tent. Reservations are required and must be made through the New York State Parks reservation system online or by phone.
Nightly fees vary: lean-tos typically cost more than open campsites, and rates change seasonally. Check the official New York State Parks website for current pricing and availability. The season runs from May through October, though exact opening and closing dates can shift year to year. Book early if you plan to visit during summer weekends, as the island's limited capacity fills quickly.
What to Bring and How to Prepare
Pack all drinking water, food, and cooking supplies before you leave the mainland. There is no potable water on the island, no store, and no fuel dock. Bring a camp stove or charcoal grill if you plan to cook; open fires are not permitted. A headlamp or lantern is essential because there is no electric lighting. Bring a first aid kit, insect repellent, and sunscreen — the river offers no shade once the sun is high.
If you are camping overnight, bring a tent even if you reserve a lean-to, because weather can change and the shelters fill quickly. Pack out all trash; there are no garbage services on the island. A portable toilet or waste system is your responsibility if you are staying multiple nights. Check the weather forecast before crossing; the St. Lawrence can develop rough conditions quickly, and small boats should not cross in high winds or heavy rain.
Rules and Regulations
New York State Parks rules apply on Mary Island. Fires are prohibited except in designated fire rings if provided. Alcohol is permitted but glass containers are not. Pets are allowed but must be leashed and under control at all times. Fishing is allowed year-round in the river, but you must have a valid New York State fishing license. Check current regulations for species-specific rules, size limits, and seasonal restrictions before you fish.
The island is protected habitat, so stay on marked trails and designated campsites. Do not disturb wildlife or remove plants. Generators are not permitted, so plan your power needs accordingly. Quiet hours typically run from 10 p.m. to 7 a.m., and loud music or noise is not tolerated.
Nearby Alternatives and Day-Use Options
If Mary Island's overnight capacity is full or you prefer not to camp, Grass Point State Park is a few miles south and offers day-use fishing access without requiring a boat. The Thousand Islands State Park system includes several other islands and mainland parks with varying levels of development. Alexandria Bay itself has hotels, restaurants, and charter fishing services if you want to base yourself on shore and day-trip to the river.
The St. Lawrence River offers excellent fishing from shore at several public access points around Alexandria Bay. Bolt's Landing and other waterfront parks provide parking and dock access for anglers who want to fish without camping. These alternatives are useful if weather prevents a safe crossing to Mary Island or if you want to explore the area before committing to an overnight stay.
Frequently Asked Questions
Can I fish from Mary Island without camping?
Yes, day use is free and you can fish from the dock or shoreline without reserving a campsite. You must still reach the island by boat, and you should plan to return to the mainland before dark because there are no lights on the island and navigation is difficult at night.
What is the best time of year to fish Mary Island?
May through June is excellent for smallmouth bass in shallow water. July and August are slower but still productive if you fish early morning and evening. September and October see strong walleye and pike activity as water cools. The park closes in late October or early November depending on weather.
Do I need a boat to visit Mary Island?
Yes, there is no bridge or ferry service. You must own a boat, rent one from Alexandria Bay, or hire a water taxi. The crossing takes 10 to 15 minutes from the nearest mainland launch.
Are there showers or bathrooms on the island?
There are vault toilets but no running water, showers, or sinks. Bring hand sanitizer and wet wipes for personal hygiene. Plan to bathe in the river if weather permits, or wait until you return to the mainland.
Can I bring my dog to Mary Island?
Yes, dogs are allowed but must be leashed at all times. Bring fresh water for your dog because the river water is not safe to drink. Clean up after your dog and pack out all waste.