TY - RPRT TI - Proceedings of the U.S. Geological Survey Eighth Biennial Geographic Information Science Workshop and first The National Map Users Conference, Denver, Colorado, May 10-13, 2011 PY - 2014 DO - 10.3133/sir20115053 UR - https://pubs.usgs.gov/publication/sir20115053 ID - sir20115053 ER -