The Pennsylvania State UniversityIndex of USGS quarter-quadrangles (3.75 minute) covering Pennsylvania. The polygons are attributed with information pertaining to the USGS/PaGS Digital Orthophoto Quarter-Quad (DOQQ) imagery collection available for download through PASDA. Including dates of image acquisition for the complete NAPP II imagery collection (1993-1995) and imagery available as of April 2003 from the NAPP III collection (1999- ).FileengPennsylvania Spatial Data Access (PASDA)PublicPennsylvania 3.75-minute quarter quadrangle boundary [Pennsylvania]DatasetsPennsylvania