In researching my family genealogy (Mohn) for Northhampton County, PA, I may have found some information on the burial location of John Mohn, Jr. and Mary Catherine (Hartzell) Mohn to answer your inquiry.
JOHN MOHN, JR. (son of JOHN MOHN) was born 1800 in NORTHAMPTON CO. PENNSYLVANIA, and died 06 Jun 1857 in GNADENHUTTEN, TUSCARAWAS CO., OHIO. He married MARY CATHERINE HARTZELL on 18 May 1824.
More About JOHN MOHN, JR.: Burial: 1857, GNADENHUTTEN CEMETERY, GNADENHUTTEN, TUSCARAWAS CO., OHIO, SECTION LL C, GRAVE 3, FIRST ROW.
More About JOHN MOHN, JR. and MARY CATHERINE HARTZELL: Marriage: 18 May 1824
Children of JOHN MOHN, JR. and MARY CATHERINE HARTZELL are:
1. NO TRACE OF THE FOUR OTHER MOHN CHILDREN, d. date unknown. 2. AURELIA CECELIA MOHN, b. 29 Nov 1825, SHONECK, NORTH HAMPTON CO., PENNSYLVANIA, d. 01 May 1912. 3. +REUBEN T. MOHN, b. 17 Feb 1827, SHONECK, NORTH HAMPTON CO., PENNSYLVANIA, d. 20 May 1917, UHRICHSVILLE, TUSCARAWAS CO., OHIO. 4. LUDWIG HENRY MOHN, b. 08 Jun 1834, GNADENHUTTEN, TUSCARAWAS CO., OHIO, d. date unknown. 5. WILHELMINE REBECCA MOHN, b. 06 Jun 1840, d. date unknown. 6. +MARY CATHERINE MOHN, b. 31 May 1844, CARROLL CO., OHIO, d. 1932. 7. DAVID JACOB MOHN, b. 26 Apr 1846, d. 16 May 1863.