Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>U.S. USGS 1:24,000 Quadrangle Series Topographic Index represents the geographic extent of USGS 1:24,000 scale topographic maps (7.5- by 7.5-minute quadrangles) for the coterminous U.S. forty-eight states and District of Columbia.</SPAN></P></DIV></DIV></DIV>