USGS Topographic 7.5-minute Quadrangle Map

A U.S. Geological Survey (USGS) topographic map use contours to
show shape and elevation of terrain. These maps divide the
United States into quadrangles bounded by two lines of latitude
and two lines of longitude. Individual topographic maps are
commonly referred to as quadrangles or quads. The smallest
topographic quadrangle commonly published by the USGS are 7.5
minute quadrangles, which measure 7.5 minutes of latitude and
longitude.