The Adirondack and St. Lawrence Railroad operated between DeKalb Junction and Hermon in St. Lawrence County, New York over a four-mile standard gauge railroad.
A parallel railroad of the Clifton Iron Company, was abandoned in the early 1870s.
Still today the right-of-way can be observed near East DeKalb.
The trains usually made connections at DeKalb Junction to the Rome, Watertown and Ogdensburg Railroad.
[1] Sunday passenger traffic ended the following year and in 1912, one of the four trains was cancelled altogether.