Thousand Islands Bridge Authority and Boldt Castle Facilities

The Thousand Islands Bridge system extends from Collins Landing near Alexandria Bay, New York to Ivy Lea near Gananoque, Ontario covering a distance of 8.5 miles and provides direct connection between US Interstate Rt. 81 and Canada’s Highway 401.
The crossing over the American channel of the St. Lawrence River, from the mainland to Wellesley Island, consists of a suspension bridge of 800 ft. (main span), with an underclearance of 150 ft. above the river. The American span from abutment to abutment is 4,500 ft.
The Canadian crossing includes the 600 ft. continuous Warren Truss span connecting Hill Island to Constance Island, a steel arch of 348 ft. spans from Constance Island to Georgina Island and a suspension bridge of 750 ft. from Georgina Island to the Canadian mainland (Ontario) with the suspension span providing 120 ft. of underclearance above the river. The Canadian span from abutment to abutment is 3,330 ft.
The boundary at the International Rift, between Wellesley Island and Hill Island, is bridged by two parallel 90 ft. rigid-frame arched spans of reinforced concrete with masonry facing. Originally there was only one bridge at the boundary or International Rift, however increased traffi c demanded twinning this crossing in 1959.
Groundbreaking ceremonies were held at Collins Landing, New York, on April 30, 1937, with several thousand people on hand for this eventful occasion,both US and Canadian.

Thousand Islands Bridge Authority

43530 Interstate 81
Collins Landing / PO Box 428
Alexandria Bay, New York 13607
Phone: (315) 482-2501
Fax: (315) 482-6064

Boldt Castle


The Thousand Islands Bridge Authority (TIBA) welcomes you to tour Boldt Castle to explore and experience an attraction like no other. Construction began on Boldt Castle in 1900 at the bidding of millionaire hotel magnate George C. Boldt as a tribute to his beloved wife Louise. Boldt Castle was designed as their summer dream home on the St. Lawrence River, in the heart of the 1000 Islands. However it was not to be, Mrs. Boldt passed away suddenly just months before the completion of the castle. Mr. Boldt was inconsolable and immediately stopped all construction on Heart Island, leaving the property vacant for over seventy years...

Today Boldt Castle, located near Alexandria Bay, NY in the famed 1000 Islands is once again becoming what it was always meant to be, the premier home and attraction in the region. Whether you are making an annual visit to see what’s new, looking for an affordable family vacation close to home or a couple seeking that romantic getaway, Boldt Castle and the Boldt Yacht House has something for you! In fact, the Castles’ legendary beauty nestled among the St Lawrence Rivers’ 1000 Islands will keep you returning year after year!

The third Saturday in June brings families together for a fun filled day of excitement at Boldt Castle on Heart Island. WPBS-DT partners with The Thousand Islands Bridge Authority and Boldt Castle to present Family Fun Day. PBS Kids characters like Clifford the Big Red Dog, Curious George, Word Girl, Super Why, Daniel Tiger and Princess Presto spend the day at Boldt Castle greeting children and their families with educational activities, storytellers, movies, crafts and planting the “Family Fun Day Garden”!

Thousand Islands Bridge Authority / Boldt Castle


PO Box 428 / Collins Landing
Alexandria Bay, NY 13607

In Season: 315-482-9724
Off Season: 315-482-2501