PA 93 enters Mifflin Township in Columbia County and immediately turns northwest to enter Briar Creek Township and cross over the Susquehanna River near the mouth of Nescopeck Creek. Upon reaching the north bank of the river, the road enters the borough of Berwick and passes over the North Shore Railroad before heading off the bridge and into the commercial downtown on South Market Street. The route immediately intersects US 11 and turns southwest to form a wrong-way concurrency with that route on the one-way pair of West 2nd Street northbound and West Front Street southbound, with each street carrying two lanes of traffic. The streets pass through the downtown before running past a mix of homes and businesses. Both directions of US 11/PA 93 merge to head west on West Front Street, which has two northbound lanes and one southbound lane. A block later, PA 93 splits from US 11 by heading northwest onto two-lane undivided Orange Street, heading through residential areas. The route heads west out of Berwick into the northeast corner of the borough of Briar Creek, passing through farmland before turning northwest near a few homes. The road enters Briar Creek Township as an unnamed road and runs through a mix of residential areas, fields, and woods. PA 93 crosses into North Centre Township and bends southwest, running through a mix of farmland and woodland with some homes. The road passes through Fowlersville and curves to the north, passing through Whitmire. The route heads through wooded areas and curves to the northwest before turning west through a mix of farmland and trees with some homes. The roadway heads into forests and crosses into Orange Township. Farther west, PA 93 enters the borough of Orangeville and becomes Berwick Road, reaching its northern terminus at an intersection with PA 487 in a residential area.