NY 398 was assigned in the early 1930s and remained unchanged until 1980, when ownership and maintenance of the highway was transferred to Columbia County.

The route progressed eastward, passing a small park and intersecting with local roads.

[6] After the local road however, the highway began to patch its way through several hills and mountains, but this did not last long.

There were a few short hills the rest of the way along NY 398, until it entered the small hamlet of Sunnyside.

[3][4] It remained unchanged until January 28, 1980, when the NY 398 designation was officially removed from the highway.