Western Coal Field

The West Kentucky Coal Field, alternatively The North Pennyrile or simply Northwest Kentucky, comprises an area in the west-central and northwestern part of the state, bounded by the Dripping Springs Escarpment and the Pennyroyal Plateau and the Ohio River, but is part of the Illinois Basin that extends into Indiana and Illinois.

In a recent effort to distinguish itself from its coal mining past, which in the last 10 years has all but completely disappeared by 2024 with only a scant few mines still operating, the area now usually refers to itself as the Green River Valley since around 2002, named for the Green River, a southern tributary that flows through every county in the region except Union and Hancock.

A transitional zone, generally defined as being part of the coalfield, is the Clifty Area, where there is no coal but some sandstone is bituminous, and has commercial value as paving material and potentially as tar sands for liquid refining.

All three counties still contain a very large amount of coal and have active mining, surface and underground, operations taking place.

This is a region that was considered to be the largest producer of coal in the world from the 1960s through part of the '80s until it dramatically dropped in the early '90s after the passage of the Clean Air Act Amendments of 1990.