Russ Strodtz wrote regardling long distance cargos

Vermiculite = Libby and Whitefish MT area

Also Perlite is a New Mexico commodity, transported
by the Santa Fe.

Diatomaceous Earth = extreme West Texas

Lompoc California on the SP was the largest producer
in the world for many years. This stuff is widely used
for filtering/purifying liquids.

Tim O'Connor