The Phosphate Dinkeys

The limestone under Lewis County carries phosphate, and for roughly forty miles of parkway the road runs through or beside the rock that holds it. What was taken out around Gordonsburg was blue rock, the bedded, unweathered grade, worked from shafts driven into the ledges rather than from open pits. The Park Service dates the discovery at Gordonsburg to about 1880, though the documented Tennessee industry starts later: blue rock was found near Knob Creek in 1891 and two tons shipped the following year, and the commercial boom runs from about 1896. Small locomotives the miners called dinkeys hauled pushcarts of ore on miniature track to a washer near Gordonsburg. Blue rock is the unweathered bed; the brown rock that made the bigger Tennessee fortunes lies further north, around Mount Pleasant in Maury County.

The shafts are still in the outcrops, some of them collapsed. So is the railway, and it is the more interesting of the two. The short path at the mine follows a graded cut that looks exactly like a sunken segment of the old Natchez Trace and is in fact the bed of the dinkey line, which is worth knowing in country where every old trench looks the same. Tennessee went on to be the second largest phosphate producer in the country, behind Florida, whose fields had opened a decade earlier and never stopped outproducing it. Gordonsburg rock went into superphosphate fertiliser. The Lewis County workings were finished well before the parkway was built through them.