Monday, August 31, 2009

Additional information on GNIS features

After you pick a feature, click its Feature Name link to display more information. A new page displays additional information including:
  • Elevation: The elevation of the feature is displayed in feet.
  • TopoZone.com link: Clicking this link goes to the TopoZone.com Web site and shows the feature location on a USGS topographic map.
  • FIPS55 Place Code: Federal Information Processing Standard (FIPS) 55 contains codes for named populated places, primary county divisions, and other locations in the United States. Click this link to display the FIPS55 code for the location; unless you know that you need this, the code isn’t very relevant for the average user.
  • Digital Raster Graphic (DRG) link: Click this link to display the feature location on a digitized version of a USGS topographic map; supplied by www.terraserver-usa.com.
  • Digital Orthophoto Quadrangle (DOQ) link: Click this link to display a black-and-white aerial photograph of the feature location, supplied by www.terraserver-usa.com.
  • Tiger Map Server: Click this link to display a road map of the feature area prepared from U.S. Census Bureau data.
  • Watershed: Click this link to visit U.S. Environmental Protection Agency (EPA) maps and information about the watershed where the feature is located.
You need an Internet connection to access the GNIS database. In addition to the online search capabilities at the GNIS Web site, you can download text files of all the features and associated information for each state. The files are quote- and comma-delimited and can be opened with your own databases and spreadsheets. The files come in compressed and uncompressed formats; if you have a slow Internet connection, download the Zip files.
Ever wanted to name a mountain or another land feature after yourself or a loved one? The U.S. Board on Geographic Names is responsible for naming and renaming features that appear on USGS maps. If there’s an unnamed geographic feature, you can propose a new name for it (or suggest a name change for an existing feature). The Board even has an online form that you can fill out. Submitting the form doesn’t guarantee you’ll automatically get some peak named after Uncle Harry; this is a rather big deal. For instructions on filling out the online form see http://geonames.usgs.gov/dgnp/dgnp.html.

Performing basic search for a GNIS feature

Follow these steps to perform a basic search for a feature:
  1. Go to the GNIS Web site at http://geonames.usgs.gov.
  2. Click the Query GNIS: U.S. and Territories link.
  3. Enter the feature name that you want to search for in the Feature Name text box.
  4. From the State or Territory drop-down list box, select the state where the feature is located.
  5. Click the Send Query button.
The more you narrow a search, the faster it is. For example, if you know the county where a feature is located, select it. If you don’t know much information about the feature, be patient. The GNIS server can be pretty slow.
If GNIS finds any records that match your search criteria, it lists all the
matching features. Figure 11-2 shows that a search for Horse Butte found
three matches. Information about the features includes
  • Feature name
  • State
  • County
  • Feature type
  • Latitude and longitude
  • USGS 7.5 minute map that the feature appears on

Sunday, August 30, 2009

Using the Geographic Names Information System (GNIS)


The Geographic Names Information System (GNIS) is the federal repository of geographic name information. The database contains information on nearly 2 million physical and cultural geographic features in the United States and its territories: a city, dam, island, school, or any other designated feature type. You can search for feature information at the GNIS Web site: http:// geonames.usgs.gov.
The GNIS search page has a number of different data fields that you can use to narrow down your search, including
  • Feature Name: This is the name of the feature you’re looking for. This can be either the whole name or a part of the name. Feature name searches aren’t case sensitive.
  • Query Variant Name?: Some features have other names in addition to their primary name. If you select the Yes radio button, records with matched variant names are displayed.
  • State or Territory: From this drop-down list, select the state or territory where the feature is located.
  • County Name: If you click the County Name button, a drop-down list box shows all the counties in the currently selected state. If you know the county where the feature is located, enter it to speed up your search.
  • Feature Type: The Feature Type drop-down list box contains all the feature types, such as bridges, canals, lakes, and populated places. If you know what the feature is, select its type.
  • Elevation Range: The Elevation Range text boxes let you search for features that occur at a certain height range; use feet when entering the range values.
  • Topo Map Name: You can confine a search to features only found within a United States Geological Survey (USGS) 7.5 minute topographic map by entering the map’s exact name.