Increases in atmospheric C have resulted in concerns about global warming and interest in finding means to sequester atmospheric C through land management strategies.  The purpose of this study was to (i) compare changes in mineral soil C over a 30-year interval and (ii) examine the role of mineral soil N forms and topography in these changes.  Soil samples were collected at permanently identified points on the Camp Branch Watershed, a second growth oak forest on the Cumberland Plateau in central Tennessee, in July of 1976 and archived.  These points were re-sampled in July of 2006 and both archived and new samples of the 0 to 10 cm increment of the mineral soil were analyzed for C and N using the same procedures.  Paired comparisons revealed changes in C and N concentration and mass were distinct to each soil series.  Changes in C concentration ranged from -13.1% to +12.0%.  Changes in C mass ranged from -11.3% to +8.3%.  Increases in C were most closely associated with increases in the C/total-N ratio.  Mineral soil N forms and C/N ratios explained 98.5% of variation in C in 1976 and 95.9% in 2006.  Regression analyses predicted upland sites to accumulate +83% more C than cove sites.  However, since topography explained <20% of variation in mineral soil N forms and C/N ratios in both years, we hypothesize that species composition and stand age were additional factors influencing mineral soil C storage.