Skip to main content

Route 7 - Grenadier Island

Poole's Resort

Trail Information

Click Map PDF at the bottom of the page for a printable trail description

Points of Interest

Boldt Castle on Heart Island (USA)

This castle is the most famous of all mansions constructed in the Thousand Islands. Wealthy hotel baron George Boldt (owner of the Waldorf Astoria in New York), a devoted husband and romantic, commissioned the castle to be built as a Valentine’s Day gift to his wife Louise. The island was renamed and its shoreline realigned to resemble the shape of a heart, and a castle with eleven buildings and a total of 120 rooms was planned. Sadly, Louise Boldt died a year before the castle was completed and George Boldt ordered construction halted, never to return to the unfinished castle. It was acquired by the Thousand Islands Bridge Authority, and was developed as a tourist attraction. Head out from Rockport south-southeast towards the eastern tip of Wellesley Island, and follow then follow the Manhattan Group south to Boldt Castle. The 10 km trip should take most of the day. Note that this extension crosses the border; Canadians will have to present a passport or birth certificate upon landing at Boldt Castle and then report to customs at Rockport upon return. Be careful of tour boats en route to this extremely popular sightseeing destination, as well as recreational and shipping vessels in the busy American channel.

West Grenadier Trails

The short loop trail begins at the docks near the western tip of the island. It passes craggy pitch pine and creeping juniper trees as it gently ascends the ridge to the western head of Grenadier. Stop at a historic turn-of-the-century picnic shelter to admire a spectacular river scene, or enjoy an island picnic. Follow the trail further as it skirts along part of the rocky southern face of the island, before turning northward beneath a maple-oak hardwood community, bright with wildflowers. Watch for poison ivy, especially trailside through the hardwoods!

Central Grenadier” Beach

A warm, sandy beach awaits paddlers who arrive at Central Grenadier”, the national park facility located on the southern side of the island in the small bay immediately west of Poverty Island. Look for the busy docks full of anchored boats! This destination offers several picnic shelters, plenty of campsites, full amenity washrooms and an extensive walking trail that leads through woods full of our avian companions and past an active beaver pond.

Historic Architecture

The old lighthouse at Sister Island, the cottages that line the southern shore of Grenadier at Pitch Pine Point, the boathouses on Tar Island, and the historic picnic pavilion circa 1900 are but some of the storied architecture of this place.

Grenadier East

A spectacular old oak stand beckons visitors to Grenadier East. Stroll past the Heffernan’s restaurant on the shore, explore the icehouse out back, or hike the trail network that connects to the old Township road that traverses the spine of the island. Three quiet campsites have recently been constructed for your enjoyment.

North Grenadier - Tourist’s Delight

River guides in the Thousand Islands made their fortunes from wealthy guests looking for adventure and delight in the natural splendour of the place. Sport fishing was the biggest attraction (no really it was that big!), though there was plenty of fun to be found. A restaurant served the best home grown food around from the eastern shores of Grenadier to hungry visitors. Before it burned down, Angler’s Inn (c. 1871), was a favorite stop for fisherman looking for a big haul of muskie. It was a favorite stop for dancers too! They gathered every summer Saturday night to socialize and enjoy the finest piano playing to be found.

Brooker’s Creek

The marshy shoreline that rims the northeastern side of Grenadier from Squaw island to Adelaide Island gives way at the mouth of Brooker’s Creek. A quiet excursion into the marsh wetland complex will reveal the wonders of the region’s shorebirds and marshbirds. The thick woods that meet the marsh are full of wildlife, and Brooker’s Creek is a favorite place for viewing. At dusk listen for the deep croak of the rare least bittern.

Tar Island Pictographs

Try to find and then discern the meaning of the ancient paintings on the granite rock faces along the southwestern corner of Tar Island.

Agricultural Settlement

Remnants of Grenadier’s farm community can be found as you walk the trail network. Imagine the horses on the cart track along the Municipal road between farms, or children skipping along to meet classmates at school.

Schooner Point Wreck

Ponder the mysterious fate of the shipwreck that lies just below the water’s surface off Schooner Point, opposite Sister Island. Look for a floating plastic bottle that marks the spot.

Ironsides Heronry (USA)

This large island is owned and managed by the Nature Conservancy. Great blue herons nest in the treetops of Ironsides Island, in fact it is one of the largest nesting colonies in New York State, and is recognized as a National Natural Landmark. Written permission is required to land on the island, but the nests can easily be admired without disturbing the birds from the water. The tall, steep rusty cliffs that rise sharply out of the water provide the reason behind the island’s name.


From the west, the boat launch in the village of Rockport is the most convenient access point that will place paddlers only a short paddle upstream of the western end of Grenadier Island. A small way-side park, located along the Thousand Islands Parkway, opposite Poole’s Resort Road, is a good launch site for daytrippers. However with roadside parking the only option, this site is not recommended for paddlers beginning an extended trip. The national park facilities at Mallorytown Landing offer the best access to the eastern end of Grenadier, although a lengthy exposed crossing is required.

Trip Length / Distance

Several short day trips are possible to the many destinations on Grenadier. A full day of paddling is required to travel the perimeter of this long, narrow island. Distance around Grenadier is 16km - to reach the west end of the island from Rockport is 2 km, and the east end from Mallorytown is 2km. Both roundtrips from A9 or A11 are 20km.


Overnight camping on Grenadier Island allows paddlers to spend an evening and then continue on extended trips. The route lies downriver of the Raft Narrows route (#6), and upriver of the Mallorytown Landing route (#8).

Notes and Cautions

Rough Waters

The water to the south of Grenadier Island is unprotected from strong winds. When the wind is up, paddlers may encounter very dangerous conditions that require strenuous paddling to overcome. Novice paddlers may prefer the more-sheltered northern side of the island.

Recreation Channel

The small craft route skirts the northern side of Grenadier, but don’t be surprised to meet powercraft along the entire route around this busy island.

Shipping Channel

The International Shipping Channel lies just off Long Schooner Island. The open water south of Grenadier Island is busy with large ocean-going craft. At Ironsides Island, the channel splits. The Canadian Middle Channel runs due west just off

the western corner of Grenadier, and the American Channel continues southwest, behind Wellesley Island.

Open Waters

Paddlers heading downriver to begin the Grenadier Island route, must navigate a wide crossing between Club Island and Tar Island, just offshore of the village of Rockport. This area is often busy with recreational craft and tour boats, and is known for its choppy waters. A similar crossing awaits paddlers departing from the national park mainland site at Mallorytown Landing, travelling south to Adelaide Island and the eastern end of Grenadier Island.

Additional Information

A bustling farming community once thrived on Grenadier Island, but today it’s mostly the summer people who remain. The bustle of activity on the island is now made by boaters, hikers and paddlers who fancy the warm sandy beaches, old fishing holes, vivid past, and abundant opportunities for observing wildlife. If the weather is fair, a circumnavigation of Grenadier Island is a splendid full-day paddle that brings you past extensive marshlands alive with noisy red-wing blackbirds, blue herons stalking prey, and perhaps an osprey circling overhead. Several landing points along the shores of Grenadier Island allow you to rest or stretch your legs on the trail network that connects human life on the island. National park facilities at the distant eastern and western tips of the island, and in the central northern and southern bays offer a full array of amenities. Awaiting you are quiet campsites, shaded picnic spots beside a sandy beach, and the historic picnic pavilion at the western head of the island where the sunsets are so peaceful!