See p. 111 GBNF: 'Near Hamburg, on bluff  overlooking Wards Hollow.  There were many people buried in this cemetery.' Only one stone remains -- the farmer stacked the stones against the fence earlier.  Richard was the son of Thomas Pitman, and married Lucinda hutchings -settled St. Charles County in 1811. (see p.179-80 Pioneer Families of Missouri).  Cemetery #21 on Pitman list in 1941, which also lists this single stone remaing.
Below info came with picture.
Near Hamburg on bluff overlooking Wards Hollow. GPS#698843-4283399   Cemetery destroyed years ago. It is thought that many burials were made there. The only stone found- Inf. Mr. John Castlio, P.O. Defiance, MO