This index is designed to inform map users of the various series of maps produced and distributed by the U.S. Geological Survey, and to assist users in selecting and purchasing maps. The index identifies quandrangle areas by reference code, map name, and scale. A map is usually named after the most prominent city, town, or natural landmark shown on it. A map is included showing the 7.5 minute quadrangle names for Texas. A detailed description of topographic map symbols and other information are included.