This layer displays areas defined as Hard to Count by the United States decennial census. Data is from the US Census Planning Database and included 2010 Response Rates, Mail Return Rates, Low Response Score, and ACS Response Rates. Learn more about US Census Hard to Count areas.
Coal Fields
This data set shows the coal fields of Alaska and the conterminous United States. Most of the material for the conterminous United States was collected from James Trumbull’s “Coal Fields of the United States, Conterminous United States” map (sheet 1, 1960). The Gulf Coast region was updated using generalized, coal-bearing geology obtained from State geologic maps. The Alaska coal fields were collected from Farrell Barnes’s “Coal Fields of the United States, Alaska” map (sheet 2, 1961).
Wind Turbine Density
This layer was created using point data of Wind Turbine locations within the U.S. from USGS. Density was calculated using a circular neighborhood of 1 mile and each cell is 1 square mile in area.
Crude Oil Pipelines
This layer represents crude oil pipelines throughout the U.S. and part of Canada.
Oil and Natural Gas Well Density
This layer was created using point data of Oil and Natural Gas wells in the United States. An Oil and Natural Gas Well is a hole drilled in the earth for the purpose of finding or producing crude oil or natural gas; or producing services related to the production of crude or natural gas. Density was calculated using a circular neighborhood of 1 mile and each cell is 1 square mile in area.
Brownfield Sites
This layer displays the locations of the Environmental Protection Agency (EPA) Assessment, Cleanup and Redevelopment Exchange System (ACRES) sites. ACRES stores information reported by EPA Brownfields grant recipients on brownfields properties assessed or cleaned up with grant funding as well as information on Targeted Brownfields Assessments performed by EPA Regions. A brownfield site consists of land previously used for industrial purposes or some commercial uses. The land may be contaminated by low concentrations of hazardous waste or pollution, and has the potential to be reused once it is cleaned up. For more information, please visit the EPA Brownfields and Land Revitalization website or the ACRES Information web page.
Natural Gas Pipelines
The U.S. natural gas pipeline network is a highly integrated network that moves natural gas throughout the continental United States. The pipeline network has about 3 million miles of mainline and other pipelines that link natural gas production areas and storage facilities with consumers. In 2017, this natural gas transportation network delivered about 25 trillion cubic feet (Tcf) of natural gas to 75 million customers.
About half of the existing mainline natural gas transmission network and a large portion of the local distribution network were installed in the 1950s and 1960s because consumer demand for natural gas more than doubled following World War II. The distribution network has continued to expand to provide natural gas service to new commercial facilities and housing developments.
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, and universities) regulated by EPA, state and local air pollution agencies. The information in AFS is used by the states to prepare State Implementation Plans (SIPs) and to track the compliance status of point sources with various regulatory programs under Clean Air Act. For more information, please visit the EPA Air Facility System web page.
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 Land Management (BLM). Within the larger area of the basins this feature class also contains smaller geographic “plays” which are defined as “A set of known or postulated oil and gas accumulations sharing similar geologic, geographic, and temporal properties, such as source rock, migration, pathway, timing, trapping mechanism, and hydrocarbon type. A play differs from a basin; a basin can include one or more plays.” This definition was originally defined by the United States Geologic Survey (USGS) and was appropriated for use in the creation of this feature class. The geographic coverage of this layer is the Continental United States, Canada, and Mexico.
Watershed Boundary Dataset, 10-Digit Hydrologic Units
The 10-Digit Hydrologic Units, a component of the Watershed Boundary Dataset (WBD), depict the fifth 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 10-digit hydrologic unit, or watershed, divides sub-basins into smaller management areas. There are 18,679 10-digit hydrologic units with an average size of 226 square miles (585 sq. km.).