The magnitude of error made in plotting the spatial position of objects mapped using simple photogrammetry methods was examined for the 61,000 ha area between the central valley and the frontal mountains of the Eighth Region which is the subject of this paper. Comparative cartography for the area was obtained from map drawn digitally using the Softcopy-Photogrammetry concept. It was concluded from these test results that the highland area on the existing cartography for the Catastro project had an absolute error close to 5% in spatial positioning derived from polygonal surveys of the surface. One conclusion was that the real surface error, excluding compensation and underestimation, was close to 12%.