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.

Road Structures

For more information on companies in this article

Related Content

  • SSL hits back over criticism of its work on the Champlain Bridge
    December 11, 2017
    The contactor building the replacement Champlain Bridge in Canada has hit back over of allegations of poor workmanship in the US$3.3 billion project. The new 3.4km cable-stayed Champlain Bridge over the St Lawrence River will have six lanes vehicle lanes and a separate cycle and pedestrian lane. Design life is 125 years and is being constructed under a public-private partnership and operating contract of 30 years after completion of construction. Work includes construction of a smaller bridge for Île des
    Read More
  • Golden route to success
    July 20, 2012
    Built in 1937 and still the ninth longest suspension bridge in the world, the Golden Gate Bridge across San Francisco Bay remains in fine shape despite its age - Andrew Bardin Williams writes The Golden Gate Bridge turned 75 years old on May 27 and continues to play a key role in the transportation, engineering, construction and ITS communities. The structure has played an important historical role, an engineering success that boosted the economy of the region. And it also led the way as the first major pub
    Read More
  • Major project to construct landmark Bay Bridge in California
    October 31, 2012
    Iconic California crossing will offer seismic safety – Adrian Greeman reports A unique single-span single-tower suspension bridge is the iconic centrepiece of a dramatic renewal of the eastern Bay Bridge in California, crossing from San Francisco to Oakland. Tourists in San Francisco sometimes mix up their bridges, identifying as the famous Golden Gate, the double suspension bridge which runs across the wide San Francisco Bay. These serially linked bridges in fact form the Bay Bridge east to Oakland whereas
    Read More
  • Parsons heading study team for I-69 bridge
    November 30, 2016
    Parsons will head the team handling the feasibility study for the proposed I-69 bridge project in the US. Parsons was awarded the package jointly by the Indiana Department of Transportation (INDOT) and the Kentucky Transportation Cabinet (KYTC) to lead the environmental review as well as to complete the preliminary design work for the I¬ 69 Ohio River Crossing project. The deal will see Parsons evaluate the feasibility and environmental impact of various routes for a new bridge across the Ohio River. Th
    Read More

Highlighted Content