Leer Complex is wholly owns of Core Natural Resources, Inc. Core Natural Resources, Inc., through its wholly owned subsidiaries ICG Tygart Valley, LLC and Wolf Run Mining Company, LLC, operates the Leer and Leer South mines, respectively.
The Leer Complex boundary comprises approximately 225 square miles (144,700 acres), which are a combination of owned and leased acreage. Approximately 77 percent is owned, 6 percent is leased and 17 percent is uncontrolled. Longwall mining operations of Leer, Leer South, and the future Leer West reserve are contained within the complex.
Core was created in January 2025 via the merger of CONSOL Energy Inc. and Arch Resources, Inc. (Arch) and is based in Canonsburg, Pennsylvania.
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Summary:
The strata of the Tygart Valley River in Barbour, Harrison, Preston, and Taylor Counties, West Virginia consists of Pennsylvanian Aged sedimentary strata of the Monongahela Group, the Conemaugh Group, and the Allegheny Formation. The Monongahela Group includes the Sewickley, Redstone, and Pittsburgh coal seams. The Pittsburgh Seam has been extensively surface and underground mined at higher elevations in the Tygart Valley River region. The Conemaugh Group coal seams include the Elk Lick, Harlem, Bakerstown, and Brush Creek. No known large-scale mining has taken place within the Conemaugh Group coal seams in the Tygart Valley River region. The Allegheny Formation includes the Upper Freeport, Lower Freeport, Upper Kittanning, Lower Kittanning, and Clarion coal seams. The Johnstown Limestone is situated between the Upper Kittanning and the Lower Kittanning coal seams. The Upper Freeport, Upper Kittanning, Lower Kittanning, and Clarion coal seams have been previously mined in the Tygart Valley River region. All other coal seams of the Allegheny Formation in the area occur in limited areal extent and are generally of insufficient thickness for mining.
Property Geology
The principal minable coal seam on the Leer Complex is the Lower Kittanning Seam, which both Leer and Leer South are actively mining. The Lower Kittanning Seam occurs in a larger area, with a higher seam thickness than all other listed seams. Leer South has also mined the Clarion Seam in the past and transports the mined Lower Kittanning Seam through the Clarion Seam to the preparation plant. The Lower Kittanning Seam reserve extends from Grafton, West Virginia south toward Phillippi, West Virginia. The Leer Complex reserve area is approximately 17 miles in length and approximately 18 miles wide.
The Lower Kittanning Seam consists primarily of a single horizon of coal with a bone coal parting, except in eastern areas of Leer where thick coal is mined due to a rider coal seam merging with the main bench. Drillholes show seam thickness ranging from 0.0 to 10.5 feet within the Leer Complex. The seam thins (< 3.0 feet) locally in pockets, to the south and east of the Leer LOM Plan and to the north and east of the northern extension of the Leer LOM Plan, as well as the western extent of both the Leer South and Leer West LOM Plans. The mineable coal seam is typically a low-ash, high thermal content, High Vol A bituminous metallurgical coal product. Parting does occur within the property and generally is between one and three feet thick. The parting does not affect the clean coal product since the coal is washed. The seam is generally continuous but is absent in areas outside the Leer Complex LOM Plans and in an area that was mined around in Leer.
Leer Mine
The Leer Mine (Leer), an active longwall mine that is developed in the eastern portion of Leer Complex, and is separated from Leer West Mine (Leer West) by the Tygart River. The extent of its Lower Kittanning Seam reserve area is situated between the towns of Grafton and Thornton, West Virginia and covers an area of approximately 26 square miles (approximately 16,640 acres). Across the reserve, the Lower Kittanning Seam consists of primarily a single bench of coal (4.7 feet average thickness) but can include a rider coal. When a rider coal is present, total seam thickness can reach approximately 10.5 feet. Exploration within Leer’s reserves show that the Lower Kittanning Seam thins to less than 3.0 feet to the south, east, and locally northward.
Leer South Mine
Leer South Mine (Leer South) is an active longwall mine situated in the southern portion of Leer Complex. The Leer South reserve in the Lower Kittanning Seam is lies over portions of the old underlying Clarion Seam workings of the closed Sentinel Mine. The Leer South reserve extends over 55 square miles (approximately 35,200 acres) from near Philippi, West Virginia toward Bridgeport, West Virginia. The Lower Kittanning Seam averages 4.83 feet in thickness across its reserve area, and thins to the south and west to less than 3.0 feet.
Leer West Mine
Leer West is a planned longwall mine that is separated from Leer to the east by the Tygart River. The Leer and Leer South Life of Mine (LOM) Plan areas can both mine portions of the Leer West reserves. Leer West reserves in the Lower Kittanning Seam cover an area of approximately 63 square miles (40,320 acres) and are situated between the towns of Rosemont and Phillipi, West Virginia. The Lower Kittanning Seam averages 4.66 feet in thickness across the reserve area. The Lower Kittanning Seam thins to the north to less than 3.0 feet.
Commodity Production
In January 2025, the Company sealed the Leer South mine’s active longwall panel in order to extinguish isolated combustion-related activity at the mine and did not resume longwall operations until December 2025.
| Commodity | Units | 2025 | 2024 |
|
Coal (metallurgical)
|
k tons
| .... | .... |
All production numbers are expressed as clean coal.
^ Guidance / Forecast.