The highway is located entirely within the town of Harrietstown in the southwest part of Franklin County.

NY 186 lies south of, and serves, the Adirondack Regional Airport.

Known as Lake Clear Road, NY 186 heads east-northeastward, crossing a pair of train tracks and later a creek.

South of the airport NY 186 intersects several local roads.

The highway turns more towards the northeast upon passing the airport, and proceeds uneventfully.