Air Facility System Sites

This layer displays the locations of regulated facilities that discharge air pollutants in the United States. The Air Facility System (AFS) contains compliance and permit data for stationary sources of air pollution (such as electric power plants, steel mills, factories, … Continued

Oil and Natural Gas Fields

The layer represents Oil and Natural Gas Fields. Generally, Oil and Natural Gas “Fields” are defined as “a low in the Earth’s crust of tectonic origin in which sediments have accumulated.” This definition was originally defined by the Bureau of … Continued

Air Quality System Sites

This layer displays the locations of air quality monitoring stations in the United States. The Air Quality System (AQS) contains ambient air pollution data collected by EPA, state, Local, and tribal air pollution control agencies from thousands of monitoring stations. … Continued

Electric Bulk Power Transmission Lines

This layer represents electric power transmission lines. Transmission Lines are the system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power system. Lines are operated at relatively high voltages … Continued

Watershed Boundary Dataset, 6-Digit Hydrologic Units

The 6-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the third level hydrologic subdivision of the United States. A 6-digit hydrologic unit may subdivide a 4-digit hydrologic unit or may be equivalent. There are 401 6-digit … Continued

Watershed Boundary Dataset, 4-Digit Hydrologic Units

The 4-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the second level hydrologic subdivision of the United States. A 4-digit hydrologic unit includes the area drained by a river system, a reach of a river and … Continued

Location Affordability Index for Family at AMI

This layer displays the estimated percentage of household income for housing and transportation for a family earning the Area Median Income (AMI). The expected values for housing and transportation are modeled by HUD using data from the US Census Bureau … Continued

Location Affordability Index for Family Below AMI

This layer displays the estimated monthly cost for housing and transportation for a low-income, single-parent family (earning 50% of the Area Median Income). The values for housing and transportation are modeled by HUD using data from the US Census Bureau … Continued

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 … Continued

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 … Continued