The Northern New York Library Network (NNYLN)  was chartered by the New York State Regents in 1965 to facilitate cooperative services among  libraries in northern New York and to improve library services within the region, which consists of  Clinton, Essex, Franklin, Jefferson, Lewis, Oswego and St. Lawrence counties, an area spanning over 10,000 square miles. The services provided by NNYLN include resource sharing programs, publications, access to research databases, specialized medical information services, regional catalogs, shared collection development, professional training programs, disaster preparedness, conservation/preservation programs, digitization, and electronic document delivery.

In addition to these services, NNYLN is also involved with the New York Heritage and New York State Historic Newspaper projects. These projects provide the public with free access to a wide range of  historical materials, including photographs, letters, diaries, yearbooks, directories, maps, and newspapers.. The New York Heritage project contains over 672,000 items from 285 different institutions and the New York State Historic Newspapers project contains over 5,400,000 pages spanning 444 titles from every county in the state. The New York State Historic Newspapers site receives over 1,200,000 page views per month, making it one of the busiest newspaper databases in the country.

NNYLN also provides continuing education services  on various topics ranging from utilizing Network services to library management and marketing. Classes are both given online as webinars and as in person workshops.

NNYLN is part of the Empire State Library Network (ESLN), an organization  comprised of  the nine reference and research library resources councils in the state. ESLN provides various support services among the nine councils, and works to provide equal access to information for all New Yorkers.