In the adjacent Delaware County, NY 23 initially follows a generally easterly routing through the Charlotte Creek valley. Here, the land gets more forested and the number of houses decrease as it crosses the county. After Davenport, a hamlet east of Oneonta, the road begins to climb onto the Catskill Plateau. By the time it intersects NY 10 at the village of Stamford, it has already reached an elevation of above sea level. Not far to the east of the NY 10 junction, it crosses the West Branch of the Delaware River, by this point a small brook as the river's source is located just to the north. It maintains this elevation during a brief, foray into Schoharie County that leads the route around a pair of mountains situated south of the county line.