The maintenance of transmission line corridors, regarding the monitoring of vegetation is performed by field survey or by air-borne LiDAR scanners. Mapped Information Systems containing the data of lands from where the corridors pass, and the applications used are important tools for the improvement of vegetation monitoring. In this paper, we suggest a concept of satellite stereo images to recover 3D-Digital Elevation Model (DEM) to track the dangerous trees that can strike power lines to cause blackouts. Blackouts occurring due to vegetation encroachments can cause massive damages which become a source of electric supply interruption to industries, businesses, and residential areas. Therefore, this new concept of satellite stereo images will prove to be low cost, less time consuming and a more accurate for the transmission line inspection against the dangerous vegetations. © 2011 IEEE.