The Upper Delaware River lies between the Appalachian Plateau physiographic province and Catskill physiographic section. The area's rolling hills vary in elevation from 800 to 2,000 feet and are characterized as a series of indistinct and irregular escarpments. Relief is generally between 300 and 500 feet, although it ranges to 700 feet in a few locations.

A marked diversity of unique land forms exist throughout the river corridor. The Delaware River Gorge has been identified by the Pennsylvania Bureau of Topographic and Geologic Survey as one of the outstanding scenic geologic features in the state. The gorge begins above Matamoras and runs north throughout most of the river segments, ranging between two and three thousand feet in width.

Geologic processes left many economically valuable deposits, including bluestone, sand and gravel, shale, and peat. The parent materials of most of the soils within the river corridor have been accumulated largely through glacial action and deposited as till or outwash from receding glaciers. Red and gray sandstone, siltstone, and shale are primary contributors to the soils.