What is the U.S. National Grid?
The U.S. National Grid (USNG) is a coordinate system designed for situations where precise and efficient location communication is a matter of life and death. With just 8 digits, a location can be pinpointed to within 10 meters in an area of 62×62 miles.
Adopted by the Federal Geographic Data Committee in 2001, USNG is based on the Military Grid Reference System (MGRS) that the U.S. Department of Defense and NATO partners developed in the late 1940s. After WWII combat operations revealed that latitude/longitude coordinates were problematic in urgent response situations, military planners devised a system teachable to an individual with an 8th grade education in 15 minutes.
USNG addresses the limitations of latitude/longitude: it uses measurements that are easier to estimate on maps, requires shorter communication transmissions that are less likely to be misspoken or misheard, and directly correlates to distances on the ground. The system works seamlessly with GPS and is more intuitive for individuals without formal navigation training. USNG has become the recognized "emergency response language of location" for the United States.
How USNG Works
USNG coordinates consist of three components that work together to pinpoint any location:
Grid Zone (15T)
6° × 8° area covering most of Minnesota and Iowa
100 km Square (VK)
100 km × 100 km area (≈ 62×62 miles)
Easting & Northing (8720 7790)
8 digits = 10 m accuracy within the 100 km square
This coordinate identifies the headquarters of the USNG Info Center in St. Paul, MN
This example identifies a location accurate to within 10 meters. Add more digits for even greater precision, or use fewer digits for broader areas.
What We Offer
- ✓ Comprehensive training materials for all skill levels
- ✓ Technical implementation resources for GIS professionals
- ✓ Operational guidance for emergency services
- ✓ Software tools and data resources
- ✓ Ongoing support through the USNG Institute
Who We Serve
General Public
Hikers, outdoor enthusiasts, and citizens learning standardized grid referencing for personal safety in areas without addresses.
GIS Professionals
Technical professionals implementing USNG in mapping systems, CAD systems, and spatial databases for emergency operations
Emergency Services
First responders, dispatchers, and emergency managers using USNG operationally for incident location and mutual aid coordination
Key Characteristics
✓ Simple
Easy-to-use alphanumeric coordinates that anyone can learn
✓ Accurate
Scalable precision from broad areas to 10-meter accuracy for emergencies
✓ Universal
Works everywhere in the United States and territories
✓ Standardized
Federal Geographic Data Committee approved standard
✓ Device-Independent
Can be used without electronic equipment
✓ Seamless
Crosses jurisdictional boundaries without conversion
History of USNG
After WWII, the U.S. Defense Mapping Agency and NATO organizations determined that latitude/longitude was problematic when precise and efficient location communication was a matter of life and death. The Military Grid Reference System (MGRS) was developed for NATO forces to coordinate operations across international boundaries.
The Public XY Mapping Project, a grassroots citizen effort, brought the USNG standard to the Federal Geographic Data Committee after conducting informal tests to determine which coordinate system best met requirements for national consistency and ease of human use.
After a series of significant hurricanes devastated the U.S. Southeast in the 1990s, the need for standardized location communication became apparent. FGDC officially adopted USNG as federal standard FGDC-STD-011-2001.
After-action reports from Hurricane Katrina and other disasters identified a national grid as critical for mutual aid responders arriving from different parts of the country.
FEMA issued memo to establish USNG standard for operational maps.
National Search and Rescue Committee designated USNG as the primary coordinate reference system for all land-based search and rescue activities in the United States.
Emergency Location Markers (ELMs) translate USNG principles into practical field application. After thorough testing with recreational users, responders, and geospatial experts, ELMs were deployed in Minnesota, Iowa, and Florida.
FEMA issued Directive 092-5 establishing USNG as official standard for operations.
USNG Emergency Location Marker programs expand to Georgia, Hawaii, Michigan, and additional states, placing standardized grid markers on trails and in remote areas.
USNG Institute is established by a national working group of concerned citizens. Early years are devoted to building administrative and operational structures. Promotion, outreach and dialogue with industry commenced mid-2025.