The boundary of Denver County, Colorado was modified to include the area occupied by Denver International Airport. Additional minor corrections were made to Denver County and Adams County. All corrections were made using data from the Census Bureau's county boundary file of Colorado.
Finally, county attribution was removed from the Niagara River between Lake Ontario and Lake Erie.
1) Navajo and Coconino in Arizona 2) Tuolumne and Mono in California 3) Lake and Chaffee in Colorado 4) Gulf and Franklin in Florida 5) Plaquemines Parish and Jefferson Parish in Louisiana 6) Mora and Taos in New Mexico 7) Otero and Chaves in New Mexico 8) Canovanas Municipio and Loiza Municipio in Puerto Rico 9) Tipton and Shelby in Tennesee 10) Loving and Winkler in Texas 11) Pecos and Terrell in Texas 12) Kerr and Bandera in Texas 13) Real and Bandera in Texas 14) San Patricio and Nueces in Texas 15) Sanpete and Jab in Utah 16) Harrisonburg City and Rockingham County in Virginia 17) Staunton City and Augusta County in Virginia 18) Lynchburg City and Campbell County in Virginia 19) Danville City and Pittsylvania County in VirginiaNumerous additional minor boundary adjustments were made throughout the country. In Puerto Rico, Florida Municipio was added and an offshore island was added to Ponce Municipio. A extra polygon within Vega Baja Municipio was merged with the rest of the municipio.
An attribute containing the area in square miles for the county was added. It was calculated by summing values in the area field for each county, which is in square meters, and multiplying the results by 0.0000003681.
U.S. Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas (FIPS 6-4): Washington, DC, National Institute of Standards and Technology.