The two-lane highway remains rural and begins to parallel Cherry Valley Creek, a tributary of the Susquehanna.

NY 166 continues northeastward, bending riverside northward past several farms until an intersection with CR 43.

[3] After CR 43, NY 166 begins winding northward through Middlefield, passing a large pond on the east side of the highway.

The route soon intersects with CR 52, where it bends to the northeast once again, passing Forest of Dozen Dads County Park before entering the hamlet of Five Points.

A short distance later, CR 33, which intersected back near Milford, terminates now in Cherry Valley.

[2] Construction began in the early 1950s on a new divided highway alignment for US 20 that bypassed Cherry Valley to the north.