A USGS Quad is a topographical map sheet published by the USGS. The map most commonly refered to as a "quad" is a sheet covering a 7.5 minute quadrangle of latitude and longitude at a scale of 1:24,000 (1 inch = 2000 feet), sometimes refered to as the 7.5 minute series. Each map sheet is named for a prominant town or landmark within the area covered by the sheet, for example the "Stanhope" quad. The USGS also publishes quadrangles at larger scales covering 15 minutes of latitude and longitude (the 15 minutes series), and other maps at even higher scale.