2000. Geological Survey (U.S.). This polygon shapefile portrays the 2000 state and county boundaries of the United States, Puerto Rico, and the U.S. Virgin Islands. The map layer ... Geological Survey (U.S.).
2000. U.S. Census Bureau. Geography Division. This polygon shapefile represents the unified school district boundaries in Iowa. School districts are geographic entities within which state, coun... U.S. Census Bureau. Geography Division.