Thousand Islands

Where the St. Lawrence River narrows between Ontario and New York State, the river’s granite bedrock rises through the surface in a scattered constellation of 1,864 islands. They range from the size of a living room — a rock, a tree, and a flagpole technically qualifying for island status under the traditional definition — to islands several kilometres long with farms, summer resorts, and year-round communities. This is the Thousand Islands, one of the most beautiful freshwater landscapes in North America, and one of the most overlooked by travellers who speed through on the 401 without stopping.

The region stretches roughly 80 kilometres from Kingston in the west to Brockville in the east, but the dense island cluster and the most dramatic scenery concentrate in the 50-kilometre stretch between Kingston and Rockport. The gateway towns of Gananoque, Rockport, and Brockville each offer boat tour operations, marina facilities, and accommodation. Kingston, 30 kilometres west, is the largest city in the region and the logical base for combining the Thousand Islands with the city’s considerable historic attractions.

The name itself comes from the Haudenosaunee description of the region — “Manatoana,” meaning garden of the Great Spirit — though the number 1,864 comes from a painstaking 1860s survey conducted to settle the boundary between Canada and the United States, which runs through the middle of the river and effectively divides the islands between two countries.

Top things to do in the Thousand Islands

Boat cruises from Gananoque and Rockport

The classic way to experience the Thousand Islands is by water, and the cruise operators based in Gananoque and Rockport have been running tours of the archipelago since the late 19th century. The standard options are one-hour, two-hour, and three-hour tours that take in varying numbers of islands, different sections of the main channel, and optional stops at landmarks including Boldt Castle on Heart Island.

The narrated tours provide historical background on the islands — the Gilded Age summer estates, the rum-running routes of Prohibition, the military history of the River — while the visual experience of moving through narrow channels with island cottages and ancient granite outcrops close on both sides is compelling in a way that photographs do not quite capture.

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Gananoque Boat Lines runs regular departures from the Gananoque town wharf throughout the summer season. Rockport Boat Lines operates similarly from Rockport, approximately 20 kilometres east of Gananoque. Both offer tours that include Heart Island and Boldt Castle access; the Boldt Castle stop adds a small separate admission fee but is well worth including.

Boldt Castle on Heart Island

Boldt Castle is the Thousand Islands’ most dramatic landmark — a six-storey Rhineland-style castle on Heart Island in the American section of the river, visible from the Canadian shore and accessible via the cruise tours that include island stop privileges. George Boldt, the Waldorf-Astoria hotel owner, began construction in 1900 as a gift to his wife Louise. When she died suddenly in 1904, he reportedly telegraphed workers to stop immediately and never returned. The castle sat unfinished and deteriorating for 73 years before the Thousand Islands Bridge Authority acquired it and began restoration in 1977.

Today the castle is substantially restored and furnished in period style, with the towers, ballroom, yacht house, and power house all accessible to visitors. The grounds include the island’s remarkable Italian gardens and the Alster Tower, a play castle for Boldt’s children built on an adjacent rock. Allow 90 minutes to two hours for a thorough visit once you are on the island.

A US customs entry stamp is not required for the brief island stop — the tour operators hold special agreements — but you should carry your passport as standard practice when crossing into US waters.

Kayaking and paddling the islands

Sea kayaking through the Thousand Islands provides access to passages and viewpoints that boat cruises cannot reach. The channels between smaller islands, the wave-washed granite shores, and the ability to pull up on uninhabited island rocks for a picnic are all experiences specific to self-propelled travel. Guided kayak tours operate from Gananoque and from several outfitters along the river, with options ranging from half-day paddles to multi-day camping expeditions with island camping permits.

The St. Lawrence Islands National Park — Canada’s smallest national park — maintains 21 island day-use areas and camping sites accessible only by water, bookable through Parks Canada’s reservation system. Camping on an island in the middle of the St. Lawrence, with freighters passing through the main shipping channel in the night, is a distinctive experience.

Touring by bicycle along the Frontenac Arch

The Frontenac Arch Corridor — the granite ridge connecting the Canadian Shield to the Adirondacks, which surfaces dramatically through the river here — has good cycling roads along both the riverfront near Kingston and the quieter county roads east of Gananoque. The 1000 Islands Parkway, which runs 37 kilometres from Gananoque to Brockville along the river shore, is a dedicated cycling and walking path on the river side with continuous views of the islands and passing ships.

The parkway is separated from highway traffic for most of its length, passes through several small beach and picnic areas, and connects the towns and villages along the river with a level, manageable route. Bicycle rentals are available in Kingston and Gananoque.

Rockport and the smaller gateway towns

Rockport — a village of perhaps 200 permanent residents — sits at the point where the river is most densely islanded. The boat landing is small and the atmosphere is genuinely low-key compared to Gananoque, which has more restaurants and accommodation and works harder at the tourism infrastructure. The Rockport Boat Lines tours from here offer a different angle on the islands than the Gananoque departures, with the two-hour tours covering the denser central section of the archipelago.

Brockville, the largest town east of Kingston in the region, has the Brockville Railway Tunnel — the oldest railway tunnel in Canada, now converted to a pedestrian walkway with light art installations — and a handsome limestone main street above the river.

When to visit the Thousand Islands

May and early June: The river is quiet, accommodation is easier to find, and the granite outcrops show their spring colours. Some cruise operations begin in late May; full schedules typically start in mid-June. Water temperatures are cold.

Late June to August: Full season. All tours, ferries, and parks services operate. The river is warm enough for swimming from island rocks. Accommodation in Gananoque books out; reservations are essential. July and August are busy but the experience of a full summer day on the river — boats, kayaks, cottages, freighters — is the authentic Thousand Islands.

September: Arguably the best month. Crowds thin noticeably after Labour Day, prices ease, the autumn light on the river is beautiful, and the maples on the larger islands begin their colour change. All major services continue through September.

October to April: Most cruise operations close by mid-October. The islands in winter — frozen river, snow-covered granite, absolute silence — are accessible to ice fishers and snowmobilers but provide a completely different experience.

Where to stay

Gananoque is the obvious base. The 1000 Islands Hotel, the Trinity House Inn (a restored 1859 stone house now operating as a boutique inn), and a range of motels along King Street provide options across most price ranges. The town has enough restaurants and a lively enough summer atmosphere to be pleasant in itself.

Kingston (30 kilometres west) provides a larger accommodation selection and access to the city’s own considerable attractions, making it a better base for travellers who want to combine the islands with Kingston’s historic sites and waterfront. See the separate Kingston guide for accommodation details.

Island cottage rentals: Several private island cottages are available for weekly rental, a completely different approach to the region that requires a boat to access but provides the experience of island life that the day-trippers are watching from their cruise boats.

Camping at St. Lawrence Islands National Park: Island camping on Grenadier Island or the Mallorytown Landing mainland site is bookable through Parks Canada’s reservation system and fills quickly for summer weekends.

Getting there and around

From Toronto: Highway 401 east, approximately 270 kilometres to Kingston and then another 30 kilometres to Gananoque — total 2.5 to 3 hours. The 401 provides a fast but scenically underwhelming approach; Highway 2 along the lake from Kingston to Gananoque is more interesting for the final section.

From Ottawa: Highway 416 south to the 401, then west — approximately 200 kilometres, under 2 hours. Ottawa visitors can approach from the east through Brockville, which is closer to the capital and offers its own river access.

Getting around the region: A car is useful for moving between the gateway towns (Gananoque, Rockport, Brockville, Kingston), but once based in one town, the boat tours handle transportation within the islands. The 1000 Islands Parkway cycling path connects Kingston and Gananoque and Brockville by bicycle. There is no inter-city bus service specifically serving the river communities.

What to eat and drink

The Thousand Islands region is not a culinary destination in the same way as Prince Edward County to the west, but the towns along the river offer decent seasonal eating. Gananoque has a growing restaurant scene concentrated around King Street and the waterfront. Fresh local pickerel — walleye — appears on menus in season and is the regional fish worth ordering.

Thousand Island dressing, the creamy pink condiment, does in fact originate in this region — reportedly created by a fishing guide’s wife in the early 1900s. The precise origin story is contested between Canadian and American claimants, but both the Gananoque area and the Thousand Islands resort hotels on the American side lay claim to it.

Gananoque’s 1000 Islands Grill and Slyce Pizza are among the better casual dining options on the main drag. Brockville, the largest eastern gateway town, has a stronger independent restaurant scene including several spots with patio views over the river. For serious dining, Kingston (30 km west) provides a significantly wider selection — the Chez Piggy, The Tett Centre Café, and several other Kingston institutions are within a half-hour drive.

The St. Lawrence River’s fresh water supports a fishing culture that is partly recreational and partly commercial. Lake trout, bass, muskellunge, and yellow perch also appear in local restaurants alongside the pickerel. Fishing charters on the river are available from Gananoque and several operators offer guided half-day and full-day fishing trips through the island channels.

The history and geography of the islands

The Thousand Islands’ origin is geological: the Frontenac Arch, a granite ridge connecting the Canadian Shield to the Adirondack Mountains of New York State, crosses the St. Lawrence at this point. As the last glaciers retreated 10,000 to 12,000 years ago, meltwater carved the river channels through this arch, leaving its highest points as the islands that now populate the river. The granite is ancient — among the oldest exposed rock in eastern North America — and its pink and grey colours visible in island outcroppings and in the limestone bluffs along the Canadian shore give the landscape a distinctive geological character.

The indigenous Haudenosaunee people knew this landscape as Manatoana, the Garden of the Great Spirit, and used the river channels for travel and fishing for thousands of years before European contact. French explorers passed through in the 17th century, and the river became a critical trade and military route throughout the colonial period. The Thousand Islands were the site of significant engagement during the War of 1812 — smuggling, naval raids, and the peculiar guerrilla warfare of the river passage feature in the local history.

The Gilded Age transformed the islands: from the 1880s through the early 20th century, American industrialists built summer estates and private islands throughout the archipelago. The Singer Castle on Dark Island, the summer cottages of the Pullman and Bourne families, and dozens of smaller private islands with boathouses and gardens represent this period of elaborate leisure that the cruise tours document from the water.

Skydeck Canada and the bridge view

The 1000 Islands Skydeck, located at the base of the Thousand Islands International Bridge at Hill Island (accessible from the Canadian side of the bridge toll plaza), stands 130 metres above the river and provides panoramic views of the island cluster that no boat tour can replicate. From above, the scale of the archipelago — islands in every direction to the horizon — and the international boundary (marked by navigation buoys running through the island channels) are visible in a single view. The observation deck and the glass-walled elevator are open from May through October.

Practical tips

Island stop tours: If you are only taking one cruise, choose a tour that includes the Boldt Castle island stop. The castle adds a fee (currently around CAD 14–18 for adults) but changes the experience from a scenic cruise into a genuine historical visit.

Booking in advance: July and August cruises can fill by mid-morning. Booking departures the day before (most operators have online reservations) or at the earliest morning slot avoids disappointment.

Weather: The St. Lawrence is a major waterway and boat tours operate in all but severe weather. Wind on the open river can make two-hour tours cold even in summer; a light layer is recommended.

Currency: Boldt Castle is in the United States and charges admission in USD. Most other services on the Canadian side price in CAD.

Photography: The early morning light on the river — before 9am in summer — is exceptional. The mist that frequently lies over the water in the first hour after sunrise, with islands emerging from it at different distances, is the photograph that most characterises the region.

Wildlife and natural environment

The Thousand Islands are not only a scenic and historical destination but an important ecological area where the Frontenac Arch creates a wildlife corridor between the Canadian Shield and the Adirondacks. The granite island habitats support breeding populations of species that are otherwise scarce in eastern Ontario: osprey nest on island rocky outcrops, great blue herons breed in rookeries on the larger undisturbed islands, and the clear water of the St. Lawrence — considerably less polluted here than in the industrial sections downriver — supports healthy populations of muskellunge, largemouth and smallmouth bass, yellow perch, and walleye.

The river current through the islands is navigable for large freighters — the St. Lawrence Seaway carries ocean-going ships from the Atlantic into the Great Lakes — and watching a large vessel pass through the island channels at close range, the ship’s hull completely disproportionate to the island landscape around it, is a characteristically Thousand Islands experience. The shipping channel depth requirements mean that some of the narrowest island passages are used by vessels that have crossed from Europe.

Great blue herons are a constant presence in the shallows around island edges throughout summer. Bald eagles, re-established in this part of Ontario after decades of decline due to DDT, are now regularly seen fishing over the river and perching in the large white pines on the island ridges. River otter, mink, and American beaver inhabit the quieter island channels, most visible at dawn and dusk from a kayak.

The underwater environment of Fathom Five and the deeper St. Lawrence channels supports invasive species that have transformed the Great Lakes ecosystem since the 19th century — sea lamprey, zebra mussels, and round goby among them. The remarkably clear water that makes the Thousand Islands and Fathom Five attractive for glass-bottom boat tours and snorkelling is partly a consequence of zebra mussel filter feeding, which has transformed water clarity but fundamentally altered the food web. The ecological story of the Great Lakes and St. Lawrence is one of the most dramatic environmental histories of any freshwater system in the world.

Is the Thousand Islands worth a detour?

Yes, decisively. The Thousand Islands is one of those Canadian destinations that Canadians themselves undervalue — a region of genuine natural beauty and historical depth that most people see only from the 401 overpass. A boat cruise alone, even the one-hour tour, reframes the landscape entirely. Two or three days gives time for Boldt Castle, a kayak rental, cycling the parkway, and exploring Kingston’s historic core to the west.

The region fits naturally into a Toronto-Ottawa or Toronto-Montreal itinerary as a two-night detour. It also works as a stand-alone weekend from Toronto without the need to go further east — the drive is manageable and the payoff is considerable.