Figure 12. Individual stratigraphic surfaces (left) and faults (right) both with and without USGS DEM data draped with high resolution oblique air photos and a geologic map overlay. Mapped GPS data is shown in the lower images as individual points. The stratigraphic surface is offset by a fault that tips out towards the left. The interpreted fault surface shows small-scale corrugations and relay zones that are captured during the mapping process. GPS mapping accurately captures these features and often forces mapped interpretations to be altered.