Skip to main content

A thousand birthday greetings for US-Canada Thousand Island Bridge

The Canada-US Thousand Island Bridge system celebrated its 80th birthday in August with presentations and an open house at its US headquarters. The 33.7km three-bridge system over the St Lawrence River took 16 months to build and was completed 10 weeks ahead of schedule. It runs from Collins Landing near Alexandria Bay in the US state of New York to the small town of Ivy Lea in the Canadian province of Ontario. The system connects US Interstate 81 and Canada’s Highway 401, a major motorway between Montre
August 21, 2018 Read time: 2 mins
The Canada-US Thousand Island Bridge system celebrated its 80th birthday in August with presentations and an open house at its US headquarters.


The 33.7km three-bridge system over the St Lawrence River took 16 months to build and was completed 10 weeks ahead of schedule. It runs from Collins Landing near Alexandria Bay in the US state of New York to the small town of Ivy Lea in the Canadian province of Ontario. The system connects US Interstate 81 and Canada’s Highway 401, a major motorway between Montreal and Toronto, ending in Windsor on the Ontario border with the US state of Michigan.

The 1,370m crossing over the American channel of the river - from the US mainland to Wellesley Island - consists of a suspension bridge with a main span of around 245m and nearly 46m of clearance above the river.

The Canadian crossing includes the 183m continuous Warren Truss span connecting Hill Island to Constance Island, a steel arch of 106m spans from Constance Island to Georgina Island and a suspension bridge of 229m from Georgina Island to the Canadian mainland. The Canadian span from abutment to abutment is 1,015m and the suspension span provides 37m of river clearance.

The boundary at the International Rift boundary – the channel between Wellesley Island and Hill Island - is bridged by two parallel 27.4m rigid-frame arched spans of reinforced concrete with masonry facing. Originally there was only one bridge at boundary but due to increased traffic it was twinned in 1959.

Operation of the Thousand Islands Bridge system is shared under a joint agreement that created the US based Thousand Islands Bridge Authority which estimates that there are 2,000 vehicle-cross the annually. The system’s original consulting engineer was Robinson and Steinman of New York City that  continues to do so today but as 3220 Parsons Transportation, notes the authority.

For more information on companies in this article

Related Content

  • Highly relevant: Denmark’s asset management for bridges
    July 12, 2019
    A well-maintained road bridge network is vital to Denmark’s economy. David Arminas caught up with Niels Pedersen, head of bridges at the Danish Road Directorate Denmark, being a country mainly of islands, relies on its bridges and tunnels to help unify the nation culturally. It also means that they are vastly more important to the economic well-being of the nation than in most other states. The World Bank has classified Denmark as a high-income economy. In 2017 it ranked 16th globally in terms of gros
  • Sandvik on drill at the Liantang/Heung Yuen Wai Boundary project
    April 4, 2018
    The Liantang/Heung Yuen Wai Boundary Control Point project is creating a seventh land crossing, including highways and tunnels, between Shenzhen in China and Hong Kong There are already two control points on the eastern side of the New Territories between China and Hong Kong - at Man Kam To and Sha Tau Kok – to access eastern Shenzhen and Guangdong. All cross-boundary traffic travelling from these points must use busy local roads in Hong Kong and Shenzhen before joining the major highway systems. The US
  • More cash for BC Trans-Canada upgrades
    August 30, 2024
    Procurement for phase 3B of the Highway 1 improvements, between Langley and Abbotsford, in the Canadian province of British Columbia will start next year.
  • China opens record-breaking bridge
    April 11, 2012
    China has opened the world's longest bridge over water, the 41.58km Jiaozhou Bay Bridge, which is said to have cost well over US$2 billion to build. It links the eastern port city of Qingdao to Huangdao Island across Jiaozhou Bay and is 4km longer than the previous longest bridge over water, the Lake Pontchartrain Causeway in Louisiana, USA. Opened in June, 2011 after four years of construction, the link is expected to carry some 30,000 vehicle/day and will reduce travel time by 30 minutes, although it is o