The county is largely covered by rolling hills divided by farmlands and forest. The area's ridges are not narrow and sharp like those in some parts of the Piedmont, and the gullies and ditches are not as abrupt. The northern part of the county between the lakes is skirted by a plateau. The highest point of the county is a prominent hill in Roxboro, where the county seat has located its water reservoir tank. Person County claims three small mountains. Hager's Mountain is north of Roxboro. Red Mountain and Mt. Tirzah are in the southeastern part of the county. The geology of the county is dominated by igneous formation, overlaid by a variety of soils. Granite boulders are strewn across the county.