What location coordinates (datum) does the Geographic Names Information System use?

All coordinates in the Geographic Names Information System database are in the North American Datum of 1983 (NAD 83). They were converted from the North American Datum of 1927 (NAD 27) in September 2005.

Related Content

Filter Total Items: 8

Why are USGS historical topographic maps referenced to outdated datums?

Many different horizontal reference datums exist, but in the United States only three datums are commonly used: The North American Datum of 1927 ( NAD27 ) uses a starting point at a base station in Meades Ranch, Kansas and the Clarke Ellipsoid to calculate the shape of the Earth. The North American Datum of 1983 ( NAD83 ) was developed when...

What is the projection, horizontal datum, vertical datum, and resolution for a USGS digital elevation model DEM?

Projection :  3DEP DEMS have different projections/coordinate systems depending on the product: 1/3-, 1-, and 2-arc-second (also the discontinued 1/9-arc-second) DEMs are not projected. They are all in geographic coordinates (latitude/longitude). 5-meter DEMs (Alaska only) are Alaska Albers Equal Area. 1-meter DEMs are in Universal Transverse...

What does the term UTM mean? Is UTM better or more accurate than latitude/longitude?

UTM is the acronym for Universal Transverse Mercator, a plane coordinate grid system named for the map projection on which it is based (Transverse Mercator). The UTM system consists of 60 zones, each 6-degrees of longitude in width. The zones are numbered 1-60, beginning at 180-degrees longitude and increasing to the east. The military uses their...

What is the State Plane Coordinate System? Can GPS provide coordinates in these values?

The State Plane Coordinate System (SPCS), which is only used in the United States, is a plane coordinate system (north-south and east-west lines are perpendicular) in which each individual state has between one to six zones, depending on the state's size and shape. This coordinate system’s high level of accuracy is achieved through the use of...

How large is the North American Datum (NAD) 27 to NAD 83 shift?

Within the conterminous 48 states, the North American Datum of 1927 (NAD 27) to the North American Datum of 1983 (NAD 83) shift of the latitude/longitude graticule (lines showing parallels of latitude and meridians of longitude for the earth) is in the range of 10-100 ground meters. Changes to UTM values are generally larger, around 200 meters,...

Why do all of the coordinates (latitude and longitude) in the Geographic Names Information System seem incorrect?

Coordinates that seem to be incorrect in the Geographic Names Information System might just be projected on a different datum from the datum used on your map or your positioning system (GPS). Most USGS maps published approximately 1940-1995 are projected on the North American Datum of 1927 (NAD27) . Later maps are projected on the North American...

How can I acquire or download Geographic Names Information System (GNIS) data?

Download Geographic Names Information System (GNIS) data using the U.S. Board on Geographic Names website . Query the database for official geographic feature names, their location attributes, variant names, and other data. Display, print, and download up to 2,000 records from a query. GNIS data can also be downloaded via The National Map...

What is the Geographic Names Information System (GNIS)?

The Geographic Names Information System (GNIS) was developed by the U.S.Geological Survey (USGS) in cooperation with the U.S. Board on Geographic Names (BGN), which maintains cooperative working relationships with state names authorities to standardize geographic names. GNIS contains information about the official names for places, features, and...
Filter Total Items: 1