Several problems of deducting and documenting the petroglyphs made in the technique of engraving, that have become almost invisible to the naked eye, are analyzed in this article. The author suggests the method of shooting planes with similar drawings by separate fragments followed by installation of received frames into a single image that has higher resolution and exceed the real size in several times. Strong zooming allows to see on the PC screen the smallest details and reveal everything that is difficult to do on the rock. Based on this image, later an electronic graphic reproduction (drawing) of petroglyphs is made. As an example, the article gives the description of Ulan-Baytog monument found in the valley of Kuda river. There were found several images that differ a lot from objects of Kurumchi culture of Middle Age known before. Stylistically they are comparable with some petroglyphs of Shishkin Rock dated to Late Neolithic or Bronze Age.