New York State Route 413

County Route 18
Map of Otsego County in central New York with CR 18 highlighted in red
Route information
Length:	34.83 mi (56.05 km)
Major junctions
South end:	NY 51 in Butternuts
	US 20 near Bridgewater
North end:	CR 2 at the Oneida County line in Plainfield
Highway system
County Routes in New York County Routes in Otsego County ← NY 412 NY 414 →

County Route 18 (CR 18) is a county-maintained highway in western Otsego County, New York, in the United States. It extends for 34.83 miles (56.05 km) from an intersection with New York State Route 51 (NY 51) in the town of Butternuts to the Oneida County line at Plainfield, where it becomes CR 2. The highway runs along the eastern bank of the Unadilla River and parallels NY 8, which follows the western bank of the river. CR 18 enters the vicinity of several villages and hamlets, including the village of New Berlin and the hamlet of Unadilla Forks.

The portion of CR 18 between Unadilla Forks and U.S. Route 20 (US 20) in Plainfield—a distance of 2.52 miles (4.06 km)—was originally maintained by the state of New York. It was added to the state highway system in 1916 and designated as New York State Route 413 c. 1931. The NY 413 designation was removed in the early 1950s.

CR 18 begins at an intersection with NY 51 in the town of Butternuts, located east of the hamlet of Mount Upton on the eastern bank of the Unadilla River. CR 18 heads northward, passing along the base of the Unadilla River valley as it heads along the east bank of the river and parallels NY 8, which runs along the western bank. As the route heads away from Mount Upton, it heads through a dense forest situated at the foot of the valley's eastern edge. The forest continues to surround CR 18 until the vicinity of Lathams Corners, where the forest gives way to open fields and smaller, isolated patches of trees.