Authoritative gazetteers such as the Geographic Names Information System (GNIS; http://geonames.usgs.gov/pls/gnispublic/) and the GEOnet Names Server (GNS; http://earth-info.nga.mil/gns/html/) generally provide single-point locations for named features, because the primary function of these gazetteers is to standardize geographic name usage. Many geospatial information services, however, would be improved if the authoritative place names from these gazetteers were associated with polygons representing the actual spatial extents of the features in question. The U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) is compiling and processing shapefiles to facilitate the retrieval of georeferenced information resources related to named oceans and seas, undersea features, coastal features and waterways, and relevant administrative areas including the U.S. Exclusive Economic Zone (EEZ) and Coastal Zone Management Program (CZMP) counties. Geospatial information systems with the capability to search user-defined, polygonal geographic areas will be able to utilize these shapefiles or secondary products derived from them, such as well-known text (WKT) representations of the individual polygons within the shapefiles. How these shapefiles are used in a given system will depend, of course, on the nature of the search algorithm.

This report provides the shapefile for CZMP counties, current for the ground condition in 2009. The report also describes a simple procedure that end users of the CZMP counties shapefile can use whenever updates become necessary because of name, boundary, or other substantial changes affecting these counties.

The purpose of the CZMP counties shapefile is to improve gazetteer-based information retrieval for coastal and nearshore regions. We extracted the shapefile from the U.S. Census Bureau MAF/TIGER database because the county polygons in this database extend offshore to the traditional 3-nautical-mile limit, which approximates the seaward boundary of the coastal zone for most states. Although state participation in the CZMP has changed in recent years (see Data Sources section), the counties selected in 2009 have been retained in the shapefile to include all coastal states. Readers requiring an authoritative list of current (2013) CZMP counties should consult the online publication, “State Coastal Zone Boundaries” (National Oceanic and Atmospheric Administration, Office of Ocean and Coastal Resource Management, 2012).