In the mid-1960s, NY 17 was rerouted onto a new limited-access highway, known as the Quickway, in the vicinity of Hancock and Cadosia. The former routing of NY 17 remained state maintained as an extension of NY 989 and NY 990P between the two locations. All of NY 990P was redesignated as NY 268 between 1989 and 1993. In the floods of 2006 between June 25 and July 5, some of the areas along NY 268 suffered serious landslides and, as a result, was temporarily closed off by the New York State Department of Transportation. The road was reopened to traffic in mid-July.
