FYI

The Coal Fields of The World.

Coal Fields of The World
Note the huge coal reserves in the United States compared to those of Western Europe. Note also the lack of coal in the southern hemisphere. Siberia has enormous deposits but they are far from population centers.

United States Coal Fields

The United States has two major coal areas often called "Western Coal" and "Eastern Coal". Kansas and Nebraska separate the two areas. Wyoming is part of the western coal area and our coal generally has lower BTU content than most eastern coal. While Wyoming coal has less energy (BTU) than eastern coal, it produces less pollution.

Coal Fields of the U.S.

Western coals were formed between 100 and 45 million years Ago in two completely different types of swamps. The earlier coal swamps (100 to 65 ma) were marginal to the Cretaceous Epeiric Sea much like the eastern swamps were some 200 million years earlier. These are the coals of Utah, Colorado, and western Wyoming.

The younger western coals (65 to 45 ma) originated in intermontane valley swamps in eastern Wyoming and SE Montana far removed from any marine influence. These are the primary producing coal beds of the west. The majority of the coal in Montana and N. Dakota, although forming at the same time, never underwent the coalification process and remained as lignite.

The differing geologic histories have resulted in coals with differing characteristics.

This is a generalized comparison:

Western coal
Subbituminous
Lower in BTU
Lower in ash
Lower in sulfur
Thicker seams Surface mining

Eastern coal
Bituminous
Higher in BTU
Higher in ash
Higher in sulfur
Thinner seams
Underground mining (some surface)

Due to the differing swamp environments, geologic age and local geology, the western coals have significant differences when compared to the Eastern coals.