NY 205 was assigned as part of the 1930 renumbering of state highways in New York to a series of substandard highways connecting the hamlets of West Oneonta and Oaksville. The route began at NY 23 northwest of Oneonta and followed what is now CR 11 and CR 11B north through the village of Laurens and along the west side of Otego Creek to Mount Vision, from where it continued to NY 80 over a highway along the east bank of the creek that ultimately became the basis for NY 205's modern routing. At this point, NY 205 turned eastward, overlapping with NY 80 to connect to NY 28 at a junction just outside Oaksville and northwest of Cooperstown. South of Hartwick, NY 205 ran adjacent to the Southern New York Railway, a scenic passenger and freight railroad that was once the corridor's main transportation artery.