List of highways in Essex County, New York

[1] Several highways within the borders of the county serve as connections to ferry landings and bridges across Lake Champlain.

Essex County is served by one Interstate Highway, I-87, known locally as the Adirondack Northway.

[2] The highway was assigned after being built in 1967 to connect Keeseville to the Clinton County line, paralleling the alignment of US 9.

[2] There are six reference routes in Essex County;[7] a seventh, NY 910L, was redesignated NY 185 on April 4, 2008, as part of a New York State Department of Transportation project to rehabilitate the Champlain Bridge.

[7] Around this time, there was an addition to the highway system, with the designation of NY 915K, a short connector leading to exit 33 on the Adirondack Northway.

The "Formed" column refers to the date that the route was assigned or extended into the county; likewise, "Removed" refers to the date that the route ceased to exist within the Essex County limits.

Green exit sign (in French and English) that has the New York State Route 9N symbol with the destinations listed as AuSable Forks and Keeseville.
Signage for exit 34 (NY 915F) along the Northway (I-87)
Three signs, from high to low: A rectangular sign that reads "EAST", a New York state highway sign, and a brown-and-yellow trail marker
NY 28N sign along with Roosevelt–Marcy Trail Marker