Thanks, John.  Your patience with us slower students is commendable.  
This thread suddenly became much more interesting late yesterday when a friend called to tell me he had been collecting, drying, and stacking buffalo chips this summer.  He said he wanted to try making some Prairie Pottery.  
Now I am wondering if I can use this gumbo clay out here for pottery.  I already know where I can score lotsa freshwater mussel shells.