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…

Watershed Boundary Dataset, 12-Digit Hydrologic Units

The 12-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the sixth level hydrologic subdivision of the United States. A hydrologic unit can accept surface water from upstream drainage areas and may define a drainage area with single or multiple outlet points. A 12-digit hydrologic unit, or subwatershed, supports water resource management…