At the end of the 19th century , `` the valley of Walnut Creek was one long mining camp , known under different names , Jerome , Diamond , Mystic , Clarksdale , Rathbun and Darby '' ( later known as Darbyville ) . At the end of the 19th century , `` the valley of Walnut Creek was one continuous mining camp , known under different names , Jerome , Diamond , Mystic , Clarksdale , Rathbun and Darby '' ( later known as Darbyville ) .