USA Coal Fields Map

This interactive map displays the locations and extents of coal fields across the United States and parts of Canada. Explore over 127 named coal fields and regions, from the Appalachian coal fields in the east to the Powder River Basin in Wyoming and the Green River region in the west.

The data comes from the U.S. Geological Survey (USGS) coal fields database, providing authoritative information on coal geology, rank classification, and regional distribution. Each coal field polygon shows detailed attributes including coal rank (from lignite to anthracite), geological age, and provincial classification.

Understanding Coal Fields and Rank Classifications

Coal fields represent geographical areas where coal deposits occur in economically significant quantities. The United States contains some of the world’s largest coal reserves, distributed across distinct geological provinces.

Coal rank indicates the degree of metamorphism (or coalification) that coal has undergone. From lowest to highest rank: lignite (brownest, lowest energy content), subbituminous coal, bituminous coal (most common for electricity generation), and anthracite (hardest, highest carbon content). The rank affects coal’s energy content, burning characteristics, and commercial applications. This map helps identify which types of coal are available in different regions for energy planning and geological research.

How to Use the Coal Fields Map

• Pan and Zoom: Navigate the map to explore coal fields across North America using standard map controls
• Click on Coal Fields: Click any colored polygon to view detailed information including field name, coal rank, geological age, province, and area measurements
• Explore Regions: Major coal-producing regions are color-coded including the Appalachian Region, Powder River Basin, and Green River Basin

Key Features of the Coal Fields Tool

• Comprehensive Coverage: View all 127+ documented coal fields across the United States and portions of Canada
• Detailed Coal Information: Access coal rank classifications (lignite, subbituminous, bituminous, anthracite), geological age periods, and provincial designations for each field
• Major Basin Identification: Explore significant coal-producing regions including the Appalachian Region, Powder River Basin, Illinois Basin, Fort Union Region, and Green River Basin
• Interactive Polygon Data: Click any coal field boundary to display precise area measurements in square miles and acres, perimeter lengths, and field boundaries
• Color-Coded Visualization: Each coal field is distinctly colored for easy identification and comparison across regions
• USGS Data Source: Data derived from authoritative U.S. Geological Survey coal field mapping and classification

Frequently Asked Questions

What coal fields are shown on this map?

The map displays 127+ coal fields across North America, including major basins like the Appalachian Region (Pennsylvania, West Virginia, Kentucky), Powder River Basin (Wyoming, Montana), Illinois Basin, Fort Union Region (North Dakota, Montana), Green River Basin (Wyoming, Utah, Colorado), and numerous smaller fields across the western United States and Alaska.

What do the different coal rank classifications mean?

Coal rank indicates the stage of coal formation. Lignite is the youngest and softest with about 25-35% carbon content. Subbituminous coal has 35-45% carbon. Bituminous coal (45-86% carbon) is the most widely used for electricity generation and steel production. Anthracite is the highest rank with 86-97% carbon, burns cleanest but is rarest. Higher rank coals generally have higher energy content per ton.

How accurate are the coal field boundaries?

The coal field boundaries are derived from U.S. Geological Survey (USGS) geological mapping data. These polygons represent the known or inferred extent of coal-bearing formations based on geological surveys, drilling data, and outcrop observations. Boundaries are generalized for regional-scale visualization and should be considered approximate for detailed project planning.

Can I download coal field data from this map?

This interactive map is designed for visualization and exploration. The underlying data is publicly available from the USGS Energy Resources Program and ArcGIS Open Data portal. For GIS analysis, you can access the source feature service at services.arcgis.com to download shapefile or GeoJSON formats of the coal fields dataset.

What is the difference between a coal field and a coal basin?

A coal basin is a large geological depression where coal-bearing sediments accumulated over millions of years. A coal field is a specific area within or sometimes synonymous with a basin where coal seams are present and potentially mineable. For example, the Powder River Basin contains multiple coal fields. Some fields like the Appalachian Region span multiple geological basins.

Why are some coal fields larger than others on the map?

Coal field size varies based on geological history and the extent of coal-bearing formations. Large fields like the Powder River Region cover thousands of square miles because coal formed across extensive ancient swamp systems. Smaller fields may represent isolated depositional environments or eroded remnants of once-larger deposits. Size doesn’t necessarily correlate with total coal reserves, as seam thickness and rank also matter.