Used to haul that stuff... if it even hints of rain, the job gets shut down...you can't even stand up on it when it's wet, let alone drive a truck and a set of doubles across it!!
It is our main industry here, well after ranching and tourism. The main use, about 90% of the product, is for drilling mud but it has hundreds of other uses from cat litter to wine clarifier and is used in foundrys mixed with coal.