At Port Jervis, New York, the river enters the Port Jervis trough. At this point, the Walpack Ridge deflects the Delaware into the Minisink Valley. It follows the southwest strike of the eroded Marcellus Formation beds along the Pennsylvania-New Jersey state line for to the end of the ridge at Walpack Bend in Walpack Township, New Jersey in the Delaware Water Gap National Recreation Area. It skirts the Kittatinny ridge, which it crosses at the Delaware Water Gap, between nearly vertical walls of sandstone, quartzite, and conglomerate.