Hoskins Mound

Back in the 1950s, if you turned South off Texas Highway 35 onto Brazoria County Road 203, it would take you past Liverpool, Texas, and Lute's fishing camp on Chocolate Bayou, and miles of featureless coastal plains.  
Eventually, on the left just before you drove off into Chocolate Bay, you would encounter a massive yellow block, several stories high and several city blocks long.
What you were seeing was sulfur that had been mined from the Hoskins Mound salt dome.  From there it was loaded onto freight cars that often made trains a mile or so long.