2 Sep 2025

Wildfire Perimeters

The layer displays historic wildland fire perimeters. The Geospatial Multi-Agency Coordination group, or GeoMAC, is an internet-based mapping tool originally designed for fire managers to access online maps of current fire locations and perimeters in the U.S. Perimeters are submitted to GeoMAC by field offices and made available to the public. Perimeter data is not the final or official perimeter for any incident and is provided for informational purposes only. The final official perimeter should be obtained from the host unit which can be determined by looking at the Unit ID for any specific fire.

2 Sep 2025

Physiographic Section Regions

This is a polygon coverage of Physiographic Divisions in the
conterminous United States. It was automated from Fenneman’s
1:7,000,000-scale map, “Physical Divisions of the United
States,” which is based on eight major 1946 divisions, 25 provinces,
and 86 sections representing distinctive areas having common
topography, rock types and structure, and geologic and
geomorphic history.

2 Sep 2025

Hydrography – Rivers & Streams

Hydrography depicts surface water, including rivers and streams, lakes and ponds, canals, coastlines, and many other water features. The Hydrography layer combines two data sets: the 2021 National Map Hydrographic Geodatabase (1:1,000,000 scale) for small to medium scales, and the 2016 National Hydrography Datataset (NHD) (1:24,000 scale) for large scale mapping. Hydrography is depicted in two layers. Rivers & Streams depicts linear hydrography, including rivers, streams, canals, pipes, and artificial paths (line networks through larger water bodies). Waterbodies includes area hydrography, including larger rivers, lakes, ponds, seas, bays, estuaries, etc.

2 Sep 2025

National Hydrography Dataset (NHD) Flowline

The National Hydrography Dataset (NHD) is used to portray surface water. The NHD represents the drainage network with features such as rivers, streams, canals, lakes, ponds, coastline, etc. The principal components of the NHD are:

  • NHDFlowline: This is the fundamental flow network consisting predominantly of stream/river and artificial path vector features. It represents the spatial geometry, carries the attributes, models the water flow, and contains linear referencing measures for locating events on the network. Additional NHDFlowline features are canal/ditch, pipeline, connector, underground conduit, and coastline.
  • NHDArea: This feature class contains many additional features of water polygons. One of the more important is the stream/river feature. It represents the aerial extent of the water in a wide stream/river with a basic set of attributes. They typically contain NHDFlowline artificial paths that are used to model the stream/river. Artificial path carries the critical attributes of the stream/river, whereas NHDArea represents the geometric extent.
  • NHDWaterbody: Basic waterbodies such as lake/pond features are represented here. They portray the spatial geometry and the attributes of the feature. These water polygons may contain NHDFlowline artificial paths to allow the representation of water flow. Other NHDWaterbody features are swamp/marsh, reservoir, playa, estuary, and ice mass.
2 Sep 2025

Current Wildland Fire Locations

This layer displays the location of current wildland fire locations. Points are symbolized based on the daily acres burned, and the current fire behavior. Data is updated daily.