The Seaway Trail was first designated in 1978 as an byway leading from the Seaway International Bridge to the Thousand Islands Bridge. It was extended southwestward across the state of New York in the mid-1980s and into Pennsylvania in 1996. The byway is recognized as a state scenic byway by both New York and Pennsylvania (the latter designation coming in 2003) and was named a National Scenic Byway in two stages. In New York, the Seaway Trail became one of the first byways in the nation to be declared a National Scenic Byway when it received the distinction in 1996. The Pennsylvania portion of the byway was added in 2005. The Seaway Trail was officially renamed the Great Lakes Seaway Trail in 2010.