"Although this miniature map was intended as a map of the railroad from Sucre to Camiri, existing and projected, it is actually a map of southeastern Bolivia, a remote region difficult of access. On it are also plotted other railways and the highways of the area, and many small towns and villages. The position of Sucre is designated by name and by the locomotive and train [upper left corner]. Camiri is designated by name and by the oil derricks [lower right corner]. The purpose of the railroad under construction at the time the stamp was issued, was to make accessible the recently developed oil fields at Camiri."

William R. Horney, "Miniature Maps of the World," Weekly Philatelic Gossip, 48:4(1949)110.