Index Grids, This statewide data set consists of polygons representing the 1:250,000 USGS Quad boundaries spanning Arizona. The Lat/Long grid has a cell size of 2 degree Longitude x 1 degree Latitude and covers an area equal to 128 USGS 7.5 minute quadrangles. Each polygon (quad) contains an attribute for the quad number, using the ALRIS quad numbering system