Declassified CORONA images provide stereo pairs that could be used for preparation of Digital Elevation Models (DEMs) and orthophotos that could be an invaluable resource in accounting historical information. In the present work, KH-9 Hexagon CORONA images of Bilaspur district, Himachal Pradesh, India are used for the generation of DEM and orthophoto using photogrammetric techniques and tools. ASTER DEM and TanDEM-X were used to validate the generated CORONA DEM. The CORONA DEM elevation profiles at three different locations were compared with ASTER DEM and TanDEM-X. These profiles match very closely with each other. The change percentage of elevation is within 1%, between CORONA DEM and ASTER DEM, and TanDEM-X when computed for random 100 points. However, the elevation at the Bhakra dam has submeter level variation when measured using CORONA DEM. According to published reports, the elevation of the Bhakra dam is 487.68 m, while that is estimated to be 487.88 m in CORONA DEM. Furthermore, Landsat-3 MSS (1979) data is used to validate the orthophoto generated from the stereo pairs. The Govind Sagar reservoir in the study area is demarcated using object-based classification and it showed a difference of 75.91 ha between CORONA orthophoto and Landsat-3 satellite images for 1979. The water bodies are extracted in the study area between 1979 and 2010 using the object-based image classification technique. The area of the water reservoir is decreased by − 7.70%, − 4.57%, and − 19.50% between 1979 and 1990, 1990 and 2000, and 2000 and 2010. We found that annual rainfall is decreasing with an increase in temperature which could be the reason for declining reservoir area. This decrease in reservoir area could also be attributed to depleting water resources, enhanced water extraction, and increased sedimentation near the reservoir. The DEM prepared using the CORONA images can be used for the representation of the earlier earth’s surface and can be used as a reference for change detection and deformation studies.