Knobloch clinker, Southern Montana, 1999 National Coal Resource Assessment (knclkg.shp)

The clinker theme represents a digital polygon coverage
showing areas where clinker is present. Clinker forms from
the natural burning of coal beds in outcrop, and consists of
baked (melted) and fused rocks that are commonly red or
red-brown in color. In this coverage, only clinker formed by
the burning of the Knobloch coal bed is represented.
Additionally, clinker of the Knobloch coal bed that is
present within the Northern Cheyenne Indian Reservation
is not shown. This theme was created specifically for the
National Coal Resources Assessment in the Northern
Rocky Mountains and Great Plains Region.