Along the way, it connects to several major east–west highways, including U.S. Route 20 (US 20) in Esperance and the New York State Thruway in Fultonville.

The route through Charleston is rural, passing through open fields and woodlands for several miles, making several sharp bends at road junctions.

Just north of a junction with Reynolds Road (unsigned CR 121), the route winds northward into the town of Glen.

Just north of the northern terminus of CR 121, the route reaches the hamlet of Glen, which is centered around a junction with NY 161.

A couple miles to the northwest of Glen, NY 30A crosses the town line and enters the village of Fultonville.

After Riverside Drive, NY 30A crosses the Mohawk River and enters the village of Fonda.

Now named South Bridge Street, the route crosses past the Village of Fonda Recreation Park.

Dropping the Old Plank Road name, NY 30A gains the South Comrie Avenue moniker as it enters the city of Johnstown.

At this junction, NY 30A begins paralleling Cayadutta Creek, winding northeast through Johnstown.

This junction marks the northern terminus of NY 30A, less than a mile south of the entrance to Adirondack Park.

Northeast of Gloversville, it followed East State Street, current County Route 154, and Riceville Road to Mayfield.

[2] The intersection with NY 30 north of the Village of Schoharie was the site of a deadly limousine crash in October 2018 that killed 20 people.