The portion of the turnpike between Duane Center and Merrillsville was designated as NY 99 as part of the 1930 renumbering of state highways in New York.

The route headed eastward as the Port Kent–Hopkinton Turnpike, passing through the small community of Duane Center before entering an isolated, wooded area of Franklin County and Adirondack Park.

[4][5] At the Franklin town line, NY 99 curved southeastward, roughly paralleling Hatch Brook as it climbed up the northeastern portion of Baldface Mountain.

Past the mountain's summit, the route continued onward, winding its way southward along Hatch Brook to a small lake known as Duck Pond.

The highway progressed southeastward, crossing over the northern branch of the Saranac River and passing through the largely undeveloped community of Merrillsville before ending at an intersection with NY 3.

In mid-2009, residents of Loon Lake petitioned the county to repair all of CR 26 and to continuously maintain the highway, citing the road's regional importance as a through route for commuters traveling to and from the village of Malone.